632691385561 has 9 divisors (see below), whose sum is σ = 635422622943. Its totient is φ = 629971848000.

The previous prime is 632691385537. The next prime is 632691385567. The reversal of 632691385561 is 165583196236.

The square root of 632691385561 is 795419.

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

632691385561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 522918443161 + 109772942400 = 723131^2 + 331320^2 .

It is not a de Polignac number, because 632691385561 - 2¹⁹ = 632690861273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (632691385567) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 199648585 + ... + 199651753.

Almost surely, 2^632691385561 is an apocalyptic number.

632691385561 is the 795419-th square number.

632691385561 is the 397710-th centered octagonal number.

It is an amenable number.

632691385561 is a deficient number, since it is larger than the sum of its proper divisors (2731237382).

632691385561 is an frugal number, since it uses more digits than its factorization.

632691385561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6840 (or 3420 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 55.

The spelling of 632691385561 in words is "six hundred thirty-two billion, six hundred ninety-one million, three hundred eighty-five thousand, five hundred sixty-one".