125661621516 has 12 divisors (see below), whose sum is σ = 293210450232. Its totient is φ = 41887207168.

The previous prime is 125661621509. The next prime is 125661621539. The reversal of 125661621516 is 615126166521.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5235900885 + ... + 5235900908.

It is an arithmetic number, because the mean of its divisors is an integer number (24434204186).

Almost surely, 2^125661621516 is an apocalyptic number.

It is an amenable number.

125661621516 is an abundant number, since it is smaller than the sum of its proper divisors (167548828716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

125661621516 is a wasteful number, since it uses less digits than its factorization.

125661621516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10471801800 (or 10471801798 counting only the distinct ones).

The product of its digits is 129600, while the sum is 42.

The spelling of 125661621516 in words is "one hundred twenty-five billion, six hundred sixty-one million, six hundred twenty-one thousand, five hundred sixteen".