28971631 has 8 divisors (see below), whose sum is σ = 31426640. Its totient is φ = 26548992.

The previous prime is 28971623. The next prime is 28971643. The reversal of 28971631 is 13617982.

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

It is a cyclic number.

It is not a de Polignac number, because 28971631 - 2³ = 28971623 is a prime.

It is a super-2 number, since 2×28971631² = 1678710805600322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28971601) 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, 6210 + ... + 9823.

It is an arithmetic number, because the mean of its divisors is an integer number (3928330).

Almost surely, 2^28971631 is an apocalyptic number.

28971631 is a deficient number, since it is larger than the sum of its proper divisors (2455009).

28971631 is a wasteful number, since it uses less digits than its factorization.

28971631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16185.

The product of its digits is 18144, while the sum is 37.

The square root of 28971631 is about 5382.5301671240. The cubic root of 28971631 is about 307.1314676350.

The spelling of 28971631 in words is "twenty-eight million, nine hundred seventy-one thousand, six hundred thirty-one".