21012403125 has 192 divisors, whose sum is σ = 42312291840. Its totient is φ = 9072000000.

The previous prime is 21012403079. The next prime is 21012403157. The reversal of 21012403125 is 52130421012.

It is not a de Polignac number, because 21012403125 - 2¹¹ = 21012401077 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 116090535 + ... + 116090715.

It is an arithmetic number, because the mean of its divisors is an integer number (220376520).

Almost surely, 2^21012403125 is an apocalyptic number.

21012403125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21012403125 is an abundant number, since it is smaller than the sum of its proper divisors (21299888715).

21012403125 is an equidigital number, since it uses as much as digits as its factorization.

21012403125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21012403125 its reverse (52130421012), we get a palindrome (73142824137).

The spelling of 21012403125 in words is "twenty-one billion, twelve million, four hundred three thousand, one hundred twenty-five".