125559305721 has 24 divisors (see below), whose sum is σ = 192426309504. Its totient is φ = 78620492160.

The previous prime is 125559305719. The next prime is 125559305723. The reversal of 125559305721 is 127503955521.

125559305721 is a `hidden beast` number, since 1 + 2 + 5 + 5 + 593 + 0 + 57 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (125559305719) and next prime (125559305723).

It is not a de Polignac number, because 125559305721 - 2¹ = 125559305719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125559305723) 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, 768045 + ... + 917066.

It is an arithmetic number, because the mean of its divisors is an integer number (8017762896).

Almost surely, 2^125559305721 is an apocalyptic number.

It is an amenable number.

125559305721 is a deficient number, since it is larger than the sum of its proper divisors (66867003783).

125559305721 is a wasteful number, since it uses less digits than its factorization.

125559305721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1685621 (or 1685618 counting only the distinct ones).

The product of its (nonzero) digits is 472500, while the sum is 45.

The spelling of 125559305721 in words is "one hundred twenty-five billion, five hundred fifty-nine million, three hundred five thousand, seven hundred twenty-one".