491386980100 has 27 divisors (see below), whose sum is σ = 1066324958517. Its totient is φ = 196551988080.

The previous prime is 491386980089. The next prime is 491386980101. The reversal of 491386980100 is 1089683194.

The square root of 491386980100 is 700990.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 176899312836 + 314487667264 = 420594^2 + 560792^2 .

It is a super-2 number, since 2×491386980100² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (491386980101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6974851 + ... + 7044949.

Almost surely, 2^491386980100 is an apocalyptic number.

491386980100 is the 700990-th square number.

It is an amenable number.

491386980100 is an abundant number, since it is smaller than the sum of its proper divisors (574937978417).

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

491386980100 is an frugal number, since it uses more digits than its factorization.

491386980100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140212 (or 70106 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 49.

Multiplying 491386980100 by its sum of digits (49), we get a square (24077962024900 = 4906930²).

The spelling of 491386980100 in words is "four hundred ninety-one billion, three hundred eighty-six million, nine hundred eighty thousand, one hundred".