645431236541 has 16 divisors (see below), whose sum is σ = 795497404800. Its totient is φ = 509950548288.

The previous prime is 645431236537. The next prime is 645431236553. The reversal of 645431236541 is 145632134546.

It is a cyclic number.

It is not a de Polignac number, because 645431236541 - 2² = 645431236537 is a prime.

It is a super-2 number, since 2×645431236541² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 645431236492 and 645431236501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645431236531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4937351 + ... + 5066388.

It is an arithmetic number, because the mean of its divisors is an integer number (49718587800).

Almost surely, 2^645431236541 is an apocalyptic number.

It is an amenable number.

645431236541 is a deficient number, since it is larger than the sum of its proper divisors (150066168259).

645431236541 is a wasteful number, since it uses less digits than its factorization.

645431236541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10004468.

The product of its digits is 1036800, while the sum is 44.

The spelling of 645431236541 in words is "six hundred forty-five billion, four hundred thirty-one million, two hundred thirty-six thousand, five hundred forty-one".