21002101125 has 32 divisors (see below), whose sum is σ = 35222753280. Its totient is φ = 11112897600.

The previous prime is 21002101097. The next prime is 21002101177. The reversal of 21002101125 is 52110120012.

It is not a de Polignac number, because 21002101125 - 2⁷ = 21002100997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 172870 + ... + 268119.

It is an arithmetic number, because the mean of its divisors is an integer number (1100711040).

Almost surely, 2^21002101125 is an apocalyptic number.

21002101125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21002101125 is a deficient number, since it is larger than the sum of its proper divisors (14220652155).

21002101125 is a wasteful number, since it uses less digits than its factorization.

21002101125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441134 (or 441124 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

Adding to 21002101125 its reverse (52110120012), we get a palindrome (73112221137).

The spelling of 21002101125 in words is "twenty-one billion, two million, one hundred one thousand, one hundred twenty-five".