389961531961 has 3 divisors (see below), whose sum is σ = 389962156431. Its totient is φ = 389960907492.

The previous prime is 389961531923. The next prime is 389961531989. The reversal of 389961531961 is 169135169983.

The square root of 389961531961 is 624469.

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

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 only one way, i.e., 64856299561 + 325105232400 = 254669^2 + 570180^2 .

It is a de Polignac number, because none of the positive numbers 2^k-389961531961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 389961531961.

It is not an unprimeable number, because it can be changed into a prime (389961531901) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 312235 + ... + 936703.

It is an arithmetic number, because the mean of its divisors is an integer number (129987385477).

Almost surely, 2^389961531961 is an apocalyptic number.

389961531961 is the 624469-th square number.

389961531961 is the 312235-th centered octagonal number.

It is an amenable number.

389961531961 is a deficient number, since it is larger than the sum of its proper divisors (624470).

389961531961 is an frugal number, since it uses more digits than its factorization.

389961531961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248938 (or 624469 counting only the distinct ones).

The product of its digits is 9447840, while the sum is 61.

The spelling of 389961531961 in words is "three hundred eighty-nine billion, nine hundred sixty-one million, five hundred thirty-one thousand, nine hundred sixty-one".