645372273546 has 256 divisors, whose sum is σ = 1928048209920. Its totient is φ = 154536802560.

The previous prime is 645372273529. The next prime is 645372273571.

645372273546 is a `hidden beast` number, since 6 + 4 + 5 + 3 + 7 + 22 + 73 + 546 = 666.

645372273546 is nontrivially palindromic in base 10.

It is a super-3 number, since 3×645372273546³ (a number of 36 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 645372273492 and 645372273501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 44695440 + ... + 44709876.

It is an arithmetic number, because the mean of its divisors is an integer number (7531438320).

Almost surely, 2^645372273546 is an apocalyptic number.

645372273546 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 645372273546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (964024104960).

645372273546 is an abundant number, since it is smaller than the sum of its proper divisors (1282675936374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645372273546 is a wasteful number, since it uses less digits than its factorization.

645372273546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15306 (or 15300 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 54.

The spelling of 645372273546 in words is "six hundred forty-five billion, three hundred seventy-two million, two hundred seventy-three thousand, five hundred forty-six".