21000123152 has 40 divisors (see below), whose sum is σ = 41855861976. Its totient is φ = 10199540736.

The previous prime is 21000123149. The next prime is 21000123181. The reversal of 21000123152 is 25132100012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1454964736 + 19545158416 = 38144^2 + 139804^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21000123152.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336518 + ... + 394010.

Almost surely, 2^21000123152 is an apocalyptic number.

It is an amenable number.

21000123152 is a deficient number, since it is larger than the sum of its proper divisors (20855738824).

21000123152 is a wasteful number, since it uses less digits than its factorization.

21000123152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58155 (or 58149 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

Adding to 21000123152 its reverse (25132100012), we get a palindrome (46132223164).

The spelling of 21000123152 in words is "twenty-one billion, one hundred twenty-three thousand, one hundred fifty-two".