645277275720 has 768 divisors, whose sum is σ = 2854239897600. Its totient is φ = 127023759360.

The previous prime is 645277275691. The next prime is 645277275749. The reversal of 645277275720 is 27572772546.

It is a happy number.

645277275720 is a `hidden beast` number, since 6 + 45 + 2 + 7 + 7 + 27 + 572 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (645277275691) and next prime (645277275749).

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

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 191 ways as a sum of consecutive naturals, for example, 14197672 + ... + 14243048.

It is an arithmetic number, because the mean of its divisors is an integer number (3716458200).

Almost surely, 2^645277275720 is an apocalyptic number.

645277275720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645277275720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1427119948800).

645277275720 is an abundant number, since it is smaller than the sum of its proper divisors (2208962621880).

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

645277275720 is a wasteful number, since it uses less digits than its factorization.

645277275720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45440 (or 45424 counting only the distinct ones).

The product of its (nonzero) digits is 11524800, while the sum is 54.

The spelling of 645277275720 in words is "six hundred forty-five billion, two hundred seventy-seven million, two hundred seventy-five thousand, seven hundred twenty".