28501631 has 4 divisors (see below), whose sum is σ = 28513992. Its totient is φ = 28489272.

The previous prime is 28501621. The next prime is 28501657. The reversal of 28501631 is 13610582.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28501631 - 2⁶ = 28501567 is a prime.

It is a super-2 number, since 2×28501631² = 1624685939320322, 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 28501631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28501621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1580 + ... + 7713.

It is an arithmetic number, because the mean of its divisors is an integer number (7128498).

Almost surely, 2^28501631 is an apocalyptic number.

28501631 is a deficient number, since it is larger than the sum of its proper divisors (12361).

28501631 is an equidigital number, since it uses as much as digits as its factorization.

28501631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12360.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 28501631 is about 5338.6918809761. The cubic root of 28501631 is about 305.4615639841.

The spelling of 28501631 in words is "twenty-eight million, five hundred one thousand, six hundred thirty-one".