21525014004 has 96 divisors (see below), whose sum is σ = 54618689664. Its totient is φ = 6558389760.

The previous prime is 21525013997. The next prime is 21525014009. The reversal of 21525014004 is 40041052512.

It is a super-2 number, since 2×21525014004² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525014009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13343902 + ... + 13345514.

It is an arithmetic number, because the mean of its divisors is an integer number (568944684).

Almost surely, 2^21525014004 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 21525014004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27309344832).

21525014004 is an abundant number, since it is smaller than the sum of its proper divisors (33093675660).

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

21525014004 is a wasteful number, since it uses less digits than its factorization.

21525014004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417 (or 2415 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21525014004 its reverse (40041052512), we get a palindrome (61566066516).

The spelling of 21525014004 in words is "twenty-one billion, five hundred twenty-five million, fourteen thousand, four".