21125206432 has 48 divisors (see below), whose sum is σ = 46834792704. Its totient is φ = 9292608000.

The previous prime is 21125206429. The next prime is 21125206433. The reversal of 21125206432 is 23460252112.

It is a super-2 number, since 2×21125206432² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21125206432.

It is not an unprimeable number, because it can be changed into a prime (21125206433) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 957069 + ... + 978892.

It is an arithmetic number, because the mean of its divisors is an integer number (975724848).

Almost surely, 2^21125206432 is an apocalyptic number.

21125206432 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21125206432 is an abundant number, since it is smaller than the sum of its proper divisors (25709586272).

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

21125206432 is a wasteful number, since it uses less digits than its factorization.

21125206432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1936013 (or 1936005 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 21125206432 its reverse (23460252112), we get a palindrome (44585458544).

The spelling of 21125206432 in words is "twenty-one billion, one hundred twenty-five million, two hundred six thousand, four hundred thirty-two".