491703021 has 8 divisors (see below), whose sum is σ = 728448960. Its totient is φ = 327801996.

The previous prime is 491703007. The next prime is 491703067. The reversal of 491703021 is 120307194.

It is not a de Polignac number, because 491703021 - 2⁵ = 491702989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 18211223 = 491703021 / (4 + 9 + 1 + 7 + 0 + 3 + 0 + 2 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491703221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9105585 + ... + 9105638.

It is an arithmetic number, because the mean of its divisors is an integer number (91056120).

Almost surely, 2^491703021 is an apocalyptic number.

It is an amenable number.

491703021 is a deficient number, since it is larger than the sum of its proper divisors (236745939).

491703021 is a wasteful number, since it uses less digits than its factorization.

491703021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18211232 (or 18211226 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 491703021 is about 22174.3775786379. The cubic root of 491703021 is about 789.2858048856.

The spelling of 491703021 in words is "four hundred ninety-one million, seven hundred three thousand, twenty-one".