645155143440 has 160 divisors (see below), whose sum is σ = 2067458245632. Its totient is φ = 166252800000.

The previous prime is 645155143429. The next prime is 645155143453. The reversal of 645155143440 is 44341551546.

645155143440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 645155143392 and 645155143401.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5153590 + ... + 5277290.

Almost surely, 2^645155143440 is an apocalyptic number.

645155143440 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 645155143440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1033729122816).

645155143440 is an abundant number, since it is smaller than the sum of its proper divisors (1422303102192).

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

645155143440 is a wasteful number, since it uses less digits than its factorization.

645155143440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124449 (or 124443 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 42.

Adding to 645155143440 its reverse (44341551546), we get a palindrome (689496694986).

The spelling of 645155143440 in words is "six hundred forty-five billion, one hundred fifty-five million, one hundred forty-three thousand, four hundred forty".