126139335921 has 9 divisors (see below), whose sum is σ = 182202802041. Its totient is φ = 84092180292.

The previous prime is 126139335911. The next prime is 126139335953. The reversal of 126139335921 is 129533931621.

The square root of 126139335921 is 355161.

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

126139335921 is a `hidden beast` number, since 1 + 2 + 613 + 9 + 3 + 3 + 5 + 9 + 21 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 126139335921 - 2²⁵ = 126105781489 is a prime.

It is a super-2 number, since 2×126139335921² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (126139335911) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1006290 + ... + 1124676.

Almost surely, 2^126139335921 is an apocalyptic number.

126139335921 is the 355161-st square number.

126139335921 is the 177581-st centered octagonal number.

It is an amenable number.

126139335921 is a deficient number, since it is larger than the sum of its proper divisors (56063466120).

126139335921 is an frugal number, since it uses more digits than its factorization.

126139335921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236780 (or 118390 counting only the distinct ones).

The product of its digits is 262440, while the sum is 45.

The spelling of 126139335921 in words is "one hundred twenty-six billion, one hundred thirty-nine million, three hundred thirty-five thousand, nine hundred twenty-one".