633128491 has 8 divisors (see below), whose sum is σ = 640442880. Its totient is φ = 625844352.

The previous prime is 633128477. The next prime is 633128533. The reversal of 633128491 is 194821336.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-633128491 is a prime.

It is a super-2 number, since 2×633128491² = 801703372231874162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 633128491.

It is not an unprimeable number, because it can be changed into a prime (633128471) 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, 35965 + ... + 50593.

It is an arithmetic number, because the mean of its divisors is an integer number (80055360).

Almost surely, 2^633128491 is an apocalyptic number.

633128491 is a deficient number, since it is larger than the sum of its proper divisors (7314389).

633128491 is a wasteful number, since it uses less digits than its factorization.

633128491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15125.

The product of its digits is 31104, while the sum is 37.

The square root of 633128491 is about 25162.0446506241. The cubic root of 633128491 is about 858.6785596266.

It can be divided in two parts, 6331 and 28491, that multiplied together give a triangular number (180376521 = T₁₈₉₉₃).

The spelling of 633128491 in words is "six hundred thirty-three million, one hundred twenty-eight thousand, four hundred ninety-one".