971772385491 has 32 divisors (see below), whose sum is σ = 1444927921920. Its totient is φ = 645480868032.

The previous prime is 971772385457. The next prime is 971772385511. The reversal of 971772385491 is 194583277179.

971772385491 is a `hidden beast` number, since 9 + 7 + 17 + 72 + 3 + 8 + 549 + 1 = 666.

It is not a de Polignac number, because 971772385491 - 2¹⁸ = 971772123347 is a prime.

It is a super-2 number, since 2×971772385491² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (971772385391) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19133056 + ... + 19183778.

It is an arithmetic number, because the mean of its divisors is an integer number (45153997560).

Almost surely, 2^971772385491 is an apocalyptic number.

971772385491 is a deficient number, since it is larger than the sum of its proper divisors (473155536429).

971772385491 is a wasteful number, since it uses less digits than its factorization.

971772385491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53312 (or 53306 counting only the distinct ones).

The product of its digits is 26671680, while the sum is 63.

The spelling of 971772385491 in words is "nine hundred seventy-one billion, seven hundred seventy-two million, three hundred eighty-five thousand, four hundred ninety-one".