125621507517553 has 4 divisors (see below), whose sum is σ = 133011007959780. Its totient is φ = 118232007075328.

The previous prime is 125621507517551. The next prime is 125621507517577. The reversal of 125621507517553 is 355715705126521.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43878806795664 + 81742700721889 = 6624108^2 + 9041167^2 .

It is a cyclic number.

It is not a de Polignac number, because 125621507517553 - 2¹ = 125621507517551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 125621507517494 and 125621507517503.

It is not an unprimeable number, because it can be changed into a prime (125621507517551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3694750221088 + ... + 3694750221121.

It is an arithmetic number, because the mean of its divisors is an integer number (33252751989945).

Almost surely, 2^{125621507517553} is an apocalyptic number.

It is an amenable number.

125621507517553 is a deficient number, since it is larger than the sum of its proper divisors (7389500442227).

125621507517553 is an equidigital number, since it uses as much as digits as its factorization.

125621507517553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7389500442226.

The product of its (nonzero) digits is 11025000, while the sum is 55.

The spelling of 125621507517553 in words is "one hundred twenty-five trillion, six hundred twenty-one billion, five hundred seven million, five hundred seventeen thousand, five hundred fifty-three".