645253626352542 has 32 divisors (see below), whose sum is σ = 1308690077207040. Its totient is φ = 212054102228640.

The previous prime is 645253626352541. The next prime is 645253626352579. The reversal of 645253626352542 is 245253626352546.

It is a super-2 number, since 2×645253626352542² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645253626352541) 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, 82120063 + ... + 89633765.

It is an arithmetic number, because the mean of its divisors is an integer number (40896564912720).

Almost surely, 2^{645253626352542} is an apocalyptic number.

645253626352542 is an abundant number, since it is smaller than the sum of its proper divisors (663436450854498).

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

645253626352542 is a wasteful number, since it uses less digits than its factorization.

645253626352542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7715368.

The product of its digits is 311040000, while the sum is 60.

The spelling of 645253626352542 in words is "six hundred forty-five trillion, two hundred fifty-three billion, six hundred twenty-six million, three hundred fifty-two thousand, five hundred forty-two".