491251851504 has 60 divisors (see below), whose sum is σ = 1376948070576. Its totient is φ = 163497494016.

The previous prime is 491251851481. The next prime is 491251851511. The reversal of 491251851504 is 405158152194.

491251851504 is a `hidden beast` number, since 4 + 9 + 12 + 51 + 85 + 1 + 504 = 666.

It is a super-3 number, since 3×491251851504³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 491251851504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2543209 + ... + 2729544.

Almost surely, 2^491251851504 is an apocalyptic number.

It is an amenable number.

491251851504 is an abundant number, since it is smaller than the sum of its proper divisors (885696219072).

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

491251851504 is a wasteful number, since it uses less digits than its factorization.

491251851504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273414 (or 5273405 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 45.

The spelling of 491251851504 in words is "four hundred ninety-one billion, two hundred fifty-one million, eight hundred fifty-one thousand, five hundred four".