21004322525 has 12 divisors (see below), whose sum is σ = 26181729024. Its totient is φ = 16715478000.

The previous prime is 21004322497. The next prime is 21004322533. The reversal of 21004322525 is 52522340012.

It is not a de Polignac number, because 21004322525 - 2⁶ = 21004322461 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21004322494 and 21004322503.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2194631 + ... + 2204180.

It is an arithmetic number, because the mean of its divisors is an integer number (2181810752).

Almost surely, 2^21004322525 is an apocalyptic number.

21004322525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21004322525 is a deficient number, since it is larger than the sum of its proper divisors (5177406499).

21004322525 is a wasteful number, since it uses less digits than its factorization.

21004322525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4399012 (or 4399007 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

Adding to 21004322525 its reverse (52522340012), we get a palindrome (73526662537).

The spelling of 21004322525 in words is "twenty-one billion, four million, three hundred twenty-two thousand, five hundred twenty-five".