28928631 has 8 divisors (see below), whose sum is σ = 39901680. Its totient is φ = 18620672.

The previous prime is 28928617. The next prime is 28928633. The reversal of 28928631 is 13682982.

It is a happy number.

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 28928631 - 2⁶ = 28928567 is a prime.

It is a super-2 number, since 2×28928631² = 1673731383068322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28928631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28928633) 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, 166170 + ... + 166343.

It is an arithmetic number, because the mean of its divisors is an integer number (4987710).

Almost surely, 2^28928631 is an apocalyptic number.

28928631 is a deficient number, since it is larger than the sum of its proper divisors (10973049).

28928631 is a wasteful number, since it uses less digits than its factorization.

28928631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332545.

The product of its digits is 41472, while the sum is 39.

The square root of 28928631 is about 5378.5342798945. The cubic root of 28928631 is about 306.9794431446.

It can be divided in two parts, 289 and 28631, that added together give a triangular number (28920 = T₂₄₀).

The spelling of 28928631 in words is "twenty-eight million, nine hundred twenty-eight thousand, six hundred thirty-one".