28437981 has 32 divisors (see below), whose sum is σ = 44943360. Its totient is φ = 15768000.

The previous prime is 28437979. The next prime is 28437989. The reversal of 28437981 is 18973482.

It is not a de Polignac number, because 28437981 - 2¹ = 28437979 is a prime.

It is a super-2 number, since 2×28437981² = 1617437526712722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28437989) 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 31 ways as a sum of consecutive naturals, for example, 64560 + ... + 64998.

It is an arithmetic number, because the mean of its divisors is an integer number (1404480).

Almost surely, 2^28437981 is an apocalyptic number.

It is an amenable number.

28437981 is a deficient number, since it is larger than the sum of its proper divisors (16505379).

28437981 is a wasteful number, since it uses less digits than its factorization.

28437981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617.

The product of its digits is 96768, while the sum is 42.

The square root of 28437981 is about 5332.7273509903. The cubic root of 28437981 is about 305.2340083557.

The spelling of 28437981 in words is "twenty-eight million, four hundred thirty-seven thousand, nine hundred eighty-one".