491990630400 has 540 divisors, whose sum is σ = 1828008541632. Its totient is φ = 131170959360.

The previous prime is 491990630359. The next prime is 491990630447. The reversal of 491990630400 is 4036099194.

491990630400 is a `hidden beast` number, since 4 + 9 + 1 + 9 + 9 + 0 + 630 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (540).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 99530329 + ... + 99535271.

Almost surely, 2^491990630400 is an apocalyptic number.

491990630400 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 491990630400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (914004270816).

491990630400 is an abundant number, since it is smaller than the sum of its proper divisors (1336017911232).

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

491990630400 is an frugal number, since it uses more digits than its factorization.

491990630400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4996 (or 4953 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The spelling of 491990630400 in words is "four hundred ninety-one billion, nine hundred ninety million, six hundred thirty thousand, four hundred".