123861059721 has 27 divisors (see below), whose sum is σ = 208132703181. Its totient is φ = 70773525144.

The previous prime is 123861059681. The next prime is 123861059771. The reversal of 123861059721 is 127950168321.

The square root of 123861059721 is 351939.

It is a perfect power (a square), and thus also a powerful number.

123861059721 is a `hidden beast` number, since 1 + 2 + 3 + 8 + 610 + 5 + 9 + 7 + 21 = 666.

It is not a de Polignac number, because 123861059721 - 2²¹ = 123858962569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (123861059771) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7382340 + ... + 7399098.

Almost surely, 2^123861059721 is an apocalyptic number.

123861059721 is the 351939-th square number.

123861059721 is the 175970-th centered octagonal number.

It is an amenable number.

123861059721 is a deficient number, since it is larger than the sum of its proper divisors (84271643460).

123861059721 is an frugal number, since it uses more digits than its factorization.

123861059721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33538 (or 16769 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 123861059721 in words is "one hundred twenty-three billion, eight hundred sixty-one million, fifty-nine thousand, seven hundred twenty-one".