642531205524 has 72 divisors (see below), whose sum is σ = 1628979079392. Its totient is φ = 197026976640.

The previous prime is 642531205507. The next prime is 642531205567. The reversal of 642531205524 is 425502135246.

It is a super-2 number, since 2×642531205524² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 53539 + ... + 1134869.

It is an arithmetic number, because the mean of its divisors is an integer number (22624709436).

Almost surely, 2^642531205524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642531205524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (814489539696).

642531205524 is an abundant number, since it is smaller than the sum of its proper divisors (986447873868).

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

642531205524 is a wasteful number, since it uses less digits than its factorization.

642531205524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081657 (or 1081642 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 39.

The spelling of 642531205524 in words is "six hundred forty-two billion, five hundred thirty-one million, two hundred five thousand, five hundred twenty-four".