971007921 has 81 divisors (see below), whose sum is σ = 1648406721. Its totient is φ = 550427904.

The previous prime is 971007871. The next prime is 971007931. The reversal of 971007921 is 129700179.

The square root of 971007921 is 31161.

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 8767521 + 962240400 = 2961^2 + 31020^2 .

It is not a de Polignac number, because 971007921 - 2¹¹ = 971005873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (971007931) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 20659720 + ... + 20659766.

Almost surely, 2^971007921 is an apocalyptic number.

971007921 is the 31161-st square number.

971007921 is the 15581-st centered octagonal number.

It is an amenable number.

971007921 is a deficient number, since it is larger than the sum of its proper divisors (677398800).

971007921 is a wasteful number, since it uses less digits than its factorization.

971007921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 36.

The cubic root of 971007921 is about 990.2410462943.

Multiplying 971007921 by its sum of digits (36), we get a square (34956285156 = 186966²).

The spelling of 971007921 in words is "nine hundred seventy-one million, seven thousand, nine hundred twenty-one".