21125636531061 has 32 divisors (see below), whose sum is σ = 29233634760960. Its totient is φ = 13553918106624.

The previous prime is 21125636531023. The next prime is 21125636531089. The reversal of 21125636531061 is 16013563652112.

It is a happy number.

It is not a de Polignac number, because 21125636531061 - 2³⁵ = 21091276792693 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 (21125636536061) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39780495 + ... + 40308051.

It is an arithmetic number, because the mean of its divisors is an integer number (913551086280).

Almost surely, 2^{21125636531061} is an apocalyptic number.

It is an amenable number.

21125636531061 is a deficient number, since it is larger than the sum of its proper divisors (8107998229899).

21125636531061 is a wasteful number, since it uses less digits than its factorization.

21125636531061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529085.

The product of its (nonzero) digits is 194400, while the sum is 42.

The spelling of 21125636531061 in words is "twenty-one trillion, one hundred twenty-five billion, six hundred thirty-six million, five hundred thirty-one thousand, sixty-one".