28631431 has 4 divisors (see below), whose sum is σ = 28976472. Its totient is φ = 28286392.

The previous prime is 28631429. The next prime is 28631443. The reversal of 28631431 is 13413682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13413682 = 2 ⋅6706841.

It is a cyclic number.

It is not a de Polignac number, because 28631431 - 2¹ = 28631429 is a prime.

It is a super-2 number, since 2×28631431² = 1639517682215522, 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 28631431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28631401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 172396 + ... + 172561.

It is an arithmetic number, because the mean of its divisors is an integer number (7244118).

Almost surely, 2^28631431 is an apocalyptic number.

28631431 is a deficient number, since it is larger than the sum of its proper divisors (345041).

28631431 is an equidigital number, since it uses as much as digits as its factorization.

28631431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345040.

The product of its digits is 3456, while the sum is 28.

The square root of 28631431 is about 5350.8346077972. The cubic root of 28631431 is about 305.9245652550.

It can be divided in two parts, 2863 and 1431, that multiplied together give a triangular number (4096953 = T₂₈₆₂).

The spelling of 28631431 in words is "twenty-eight million, six hundred thirty-one thousand, four hundred thirty-one".