621139450491 has 32 divisors (see below), whose sum is σ = 1052016076800. Its totient is φ = 354818232000.

The previous prime is 621139450439. The next prime is 621139450493. The reversal of 621139450491 is 194054931126.

621139450491 is a `hidden beast` number, since 6 + 2 + 1 + 139 + 4 + 504 + 9 + 1 = 666.

It is not a de Polignac number, because 621139450491 - 2¹¹ = 621139448443 is a prime.

It is a super-2 number, since 2×621139450491² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (621139450493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19630 + ... + 1114748.

It is an arithmetic number, because the mean of its divisors is an integer number (32875502400).

Almost surely, 2^621139450491 is an apocalyptic number.

621139450491 is a deficient number, since it is larger than the sum of its proper divisors (430876626309).

621139450491 is a wasteful number, since it uses less digits than its factorization.

621139450491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098136 (or 1098130 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 621139450491 in words is "six hundred twenty-one billion, one hundred thirty-nine million, four hundred fifty thousand, four hundred ninety-one".