28737731 has 4 divisors (see below), whose sum is σ = 31350264. Its totient is φ = 26125200.

The previous prime is 28737719. The next prime is 28737749. The reversal of 28737731 is 13773782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28737731 is a prime.

It is a super-2 number, since 2×28737731² = 1651714366056722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28737791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1306250 + ... + 1306271.

It is an arithmetic number, because the mean of its divisors is an integer number (7837566).

Almost surely, 2^28737731 is an apocalyptic number.

28737731 is a deficient number, since it is larger than the sum of its proper divisors (2612533).

28737731 is a wasteful number, since it uses less digits than its factorization.

28737731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2612532.

The product of its digits is 49392, while the sum is 38.

The square root of 28737731 is about 5360.7584351470. The cubic root of 28737731 is about 306.3027000242.

The spelling of 28737731 in words is "twenty-eight million, seven hundred thirty-seven thousand, seven hundred thirty-one".