21123310252 has 36 divisors (see below), whose sum is σ = 41204168208. Its totient is φ = 9466256800.

The previous prime is 21123310199. The next prime is 21123310253. The reversal of 21123310252 is 25201332112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21123310253) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 272983 + ... + 341710.

It is an arithmetic number, because the mean of its divisors is an integer number (1144560228).

Almost surely, 2^21123310252 is an apocalyptic number.

21123310252 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21123310252 is a deficient number, since it is larger than the sum of its proper divisors (20080857956).

21123310252 is a wasteful number, since it uses less digits than its factorization.

21123310252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614790 (or 614777 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21123310252 its reverse (25201332112), we get a palindrome (46324642364).

The spelling of 21123310252 in words is "twenty-one billion, one hundred twenty-three million, three hundred ten thousand, two hundred fifty-two".