123215550021 has 24 divisors (see below), whose sum is σ = 185753018880. Its totient is φ = 78556654176.

The previous prime is 123215550011. The next prime is 123215550043. The reversal of 123215550021 is 120055512321.

123215550021 is a `hidden beast` number, since 1 + 2 + 3 + 2 + 155 + 500 + 2 + 1 = 666.

It is not a de Polignac number, because 123215550021 - 2¹⁹ = 123215025733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123215550011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1036375 + ... + 1149131.

It is an arithmetic number, because the mean of its divisors is an integer number (7739709120).

Almost surely, 2^123215550021 is an apocalyptic number.

It is an amenable number.

123215550021 is a deficient number, since it is larger than the sum of its proper divisors (62537468859).

123215550021 is a wasteful number, since it uses less digits than its factorization.

123215550021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118065 (or 118062 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The spelling of 123215550021 in words is "one hundred twenty-three billion, two hundred fifteen million, five hundred fifty thousand, twenty-one".