28742757 has 4 divisors (see below), whose sum is σ = 38323680. Its totient is φ = 19161836.

The previous prime is 28742731. The next prime is 28742759. The reversal of 28742757 is 75724782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28742757 - 2⁷ = 28742629 is a prime.

It is a super-2 number, since 2×28742757² = 1652292159922098, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28742759) 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, 4790457 + ... + 4790462.

It is an arithmetic number, because the mean of its divisors is an integer number (9580920).

Almost surely, 2^28742757 is an apocalyptic number.

It is an amenable number.

28742757 is a deficient number, since it is larger than the sum of its proper divisors (9580923).

28742757 is an equidigital number, since it uses as much as digits as its factorization.

28742757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9580922.

The product of its digits is 219520, while the sum is 42.

The square root of 28742757 is about 5361.2271916045. The cubic root of 28742757 is about 306.3205556166.

The spelling of 28742757 in words is "twenty-eight million, seven hundred forty-two thousand, seven hundred fifty-seven".