491021356 has 36 divisors (see below), whose sum is σ = 1004682000. Its totient is φ = 209363616.

The previous prime is 491021329. The next prime is 491021357. The reversal of 491021356 is 653120194.

It is a super-2 number, since 2×491021356² = 482203944096157472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (491021357) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32710 + ... + 45298.

Almost surely, 2^491021356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491021356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (502341000).

491021356 is an abundant number, since it is smaller than the sum of its proper divisors (513660644).

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

491021356 is a wasteful number, since it uses less digits than its factorization.

491021356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12806 (or 12797 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 491021356 is about 22159.0016923146. The cubic root of 491021356 is about 788.9208980848.

The spelling of 491021356 in words is "four hundred ninety-one million, twenty-one thousand, three hundred fifty-six".