28691937 has 24 divisors (see below), whose sum is σ = 44105256. Its totient is φ = 17911296.

The previous prime is 28691917. The next prime is 28691941. The reversal of 28691937 is 73919682.

It can be written as a sum of positive squares in 4 ways, for example, as 12362256 + 16329681 = 3516^2 + 4041^2 .

It is not a de Polignac number, because 28691937 - 2¹¹ = 28689889 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28691892 and 28691901.

It is not an unprimeable number, because it can be changed into a prime (28691917) 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, 42043 + ... + 42719.

It is an arithmetic number, because the mean of its divisors is an integer number (1837719).

Almost surely, 2^28691937 is an apocalyptic number.

It is an amenable number.

28691937 is a deficient number, since it is larger than the sum of its proper divisors (15413319).

28691937 is a wasteful number, since it uses less digits than its factorization.

28691937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977 (or 974 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 28691937 is about 5356.4855082414. The cubic root of 28691937 is about 306.1399142299.

The spelling of 28691937 in words is "twenty-eight million, six hundred ninety-one thousand, nine hundred thirty-seven".