761973613921 has 27 divisors (see below), whose sum is σ = 836189978169. Its totient is φ = 694027094592.

The previous prime is 761973613889. The next prime is 761973613993. The reversal of 761973613921 is 129316379167.

The square root of 761973613921 is 872911.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1303571025 + 760670042896 = 36105^2 + 872164^2 .

It is not a de Polignac number, because 761973613921 - 2⁵ = 761973613889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (761973613321) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 941870565 + ... + 941871373.

Almost surely, 2^761973613921 is an apocalyptic number.

761973613921 is the 872911-st square number.

761973613921 is the 436456-th centered octagonal number.

It is an amenable number.

761973613921 is a deficient number, since it is larger than the sum of its proper divisors (74216364248).

761973613921 is an frugal number, since it uses more digits than its factorization.

761973613921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1810 (or 905 counting only the distinct ones).

The product of its digits is 2571912, while the sum is 55.

The spelling of 761973613921 in words is "seven hundred sixty-one billion, nine hundred seventy-three million, six hundred thirteen thousand, nine hundred twenty-one".