491651172 has 36 divisors (see below), whose sum is σ = 1273100556. Its totient is φ = 159886080.

The previous prime is 491651137. The next prime is 491651179. The reversal of 491651172 is 271156194.

It can be written as a sum of positive squares in 2 ways, for example, as 228432996 + 263218176 = 15114^2 + 16224^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (491651179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165073 + ... + 168024.

Almost surely, 2^491651172 is an apocalyptic number.

It is an amenable number.

491651172 is an abundant number, since it is smaller than the sum of its proper divisors (781449384).

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

491651172 is a wasteful number, since it uses less digits than its factorization.

491651172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333148 (or 333143 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 491651172 is about 22173.2084281910. The cubic root of 491651172 is about 789.2580610942.

The spelling of 491651172 in words is "four hundred ninety-one million, six hundred fifty-one thousand, one hundred seventy-two".