491922512640 has 1296 divisors, whose sum is σ = 2012070741408. Its totient is φ = 114375131136.

The previous prime is 491922512617. The next prime is 491922512657. The reversal of 491922512640 is 46215229194.

491922512640 is a `hidden beast` number, since 4 + 9 + 1 + 92 + 2 + 512 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1296).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1459710552 + ... + 1459710888.

Almost surely, 2^491922512640 is an apocalyptic number.

491922512640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491922512640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1006035370704).

491922512640 is an abundant number, since it is smaller than the sum of its proper divisors (1520148228768).

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

491922512640 is a wasteful number, since it uses less digits than its factorization.

491922512640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 379 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 491922512640 in words is "four hundred ninety-one billion, nine hundred twenty-two million, five hundred twelve thousand, six hundred forty".