125744717621 has 4 divisors (see below), whose sum is σ = 125745465132. Its totient is φ = 125743970112.

The previous prime is 125744717617. The next prime is 125744717647. The reversal of 125744717621 is 126717447521.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 29203392100 + 96541325521 = 170890^2 + 310711^2 .

It is a cyclic number.

It is not a de Polignac number, because 125744717621 - 2² = 125744717617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125744711621) 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, 9725 + ... + 501581.

It is an arithmetic number, because the mean of its divisors is an integer number (31436366283).

Almost surely, 2^125744717621 is an apocalyptic number.

It is an amenable number.

125744717621 is a deficient number, since it is larger than the sum of its proper divisors (747511).

125744717621 is an equidigital number, since it uses as much as digits as its factorization.

125744717621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747510.

The product of its digits is 658560, while the sum is 47.

The spelling of 125744717621 in words is "one hundred twenty-five billion, seven hundred forty-four million, seven hundred seventeen thousand, six hundred twenty-one".