491111920 has 80 divisors (see below), whose sum is σ = 1269418752. Its totient is φ = 175472640.

The previous prime is 491111911. The next prime is 491111923. The reversal of 491111920 is 29111194.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491111923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24624 + ... + 39856.

Almost surely, 2^491111920 is an apocalyptic number.

491111920 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 491111920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (634709376).

491111920 is an abundant number, since it is smaller than the sum of its proper divisors (778306832).

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

491111920 is a wasteful number, since it uses less digits than its factorization.

491111920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15290 (or 15284 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 491111920 is about 22161.0451017094. The cubic root of 491111920 is about 788.9693979712.

The spelling of 491111920 in words is "four hundred ninety-one million, one hundred eleven thousand, nine hundred twenty".