491972540 has 24 divisors (see below), whose sum is σ = 1045593360. Its totient is φ = 194417408.

The previous prime is 491972527. The next prime is 491972549. The reversal of 491972540 is 45279194.

It is a super-2 number, since 2×491972540² = 484073960228103200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491972549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146525 + ... + 149844.

It is an arithmetic number, because the mean of its divisors is an integer number (43566390).

Almost surely, 2^491972540 is an apocalyptic number.

It is an amenable number.

491972540 is an abundant number, since it is smaller than the sum of its proper divisors (553620820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

491972540 is a wasteful number, since it uses less digits than its factorization.

491972540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296461 (or 296459 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 491972540 is about 22180.4540079774. The cubic root of 491972540 is about 789.4299899295.

The spelling of 491972540 in words is "four hundred ninety-one million, nine hundred seventy-two thousand, five hundred forty".