971506561 has 9 divisors (see below), whose sum is σ = 987632193. Its totient is φ = 955641540.

The previous prime is 971506553. The next prime is 971506573. The reversal of 971506561 is 165605179.

The square root of 971506561 is 31169.

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

It is not a de Polignac number, because 971506561 - 2³ = 971506553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (971506511) 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, 2212780 + ... + 2213218.

Almost surely, 2^971506561 is an apocalyptic number.

971506561 is the 31169-th square number.

971506561 is the 15585-th centered octagonal number.

It is an amenable number.

971506561 is a deficient number, since it is larger than the sum of its proper divisors (16125632).

971506561 is an frugal number, since it uses more digits than its factorization.

971506561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 56700, while the sum is 40.

The cubic root of 971506561 is about 990.4105228717.

The spelling of 971506561 in words is "nine hundred seventy-one million, five hundred six thousand, five hundred sixty-one".