63172991 has 8 divisors (see below), whose sum is σ = 74687520. Its totient is φ = 52280928.

The previous prime is 63172987. The next prime is 63173017. The reversal of 63172991 is 19927136.

It is a happy number.

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

It is not a de Polignac number, because 63172991 - 2² = 63172987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63172931) 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, 155396 + ... + 155801.

It is an arithmetic number, because the mean of its divisors is an integer number (9335940).

Almost surely, 2^63172991 is an apocalyptic number.

63172991 is a deficient number, since it is larger than the sum of its proper divisors (11514529).

63172991 is a wasteful number, since it uses less digits than its factorization.

63172991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311233.

The product of its digits is 20412, while the sum is 38.

The square root of 63172991 is about 7948.1438713702. The cubic root of 63172991 is about 398.2695895773.

The spelling of 63172991 in words is "sixty-three million, one hundred seventy-two thousand, nine hundred ninety-one".