28719831 has 24 divisors (see below), whose sum is σ = 46087920. Its totient is φ = 15843072.

The previous prime is 28719827. The next prime is 28719833. The reversal of 28719831 is 13891782.

It is not a de Polignac number, because 28719831 - 2² = 28719827 is a prime.

It is a super-2 number, since 2×28719831² = 1649657385337122, 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 28719831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28719833) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 895 + ... + 7631.

It is an arithmetic number, because the mean of its divisors is an integer number (1920330).

Almost surely, 2^28719831 is an apocalyptic number.

28719831 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28719831 is a deficient number, since it is larger than the sum of its proper divisors (17368089).

28719831 is a wasteful number, since it uses less digits than its factorization.

28719831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6783 (or 6776 counting only the distinct ones).

The product of its digits is 24192, while the sum is 39.

The square root of 28719831 is about 5359.0886352065. The cubic root of 28719831 is about 306.2390907679.

The spelling of 28719831 in words is "twenty-eight million, seven hundred nineteen thousand, eight hundred thirty-one".