531105021000021 has 64 divisors (see below), whose sum is σ = 780653317441536. Its totient is φ = 319189473657600.

The previous prime is 531105020999981. The next prime is 531105021000067. The reversal of 531105021000021 is 120000120501135.

It is not a de Polignac number, because 531105021000021 - 2²¹ = 531105018902869 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531105021080021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3435916666 + ... + 3436071236.

It is an arithmetic number, because the mean of its divisors is an integer number (12197708085024).

Almost surely, 2^{531105021000021} is an apocalyptic number.

It is an amenable number.

531105021000021 is a deficient number, since it is larger than the sum of its proper divisors (249548296441515).

531105021000021 is a wasteful number, since it uses less digits than its factorization.

531105021000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166362.

The product of its (nonzero) digits is 300, while the sum is 21.

Adding to 531105021000021 its reverse (120000120501135), we get a palindrome (651105141501156).

The spelling of 531105021000021 in words is "five hundred thirty-one trillion, one hundred five billion, twenty-one million, twenty-one", and thus it is an aban number.