28751861 has 4 divisors (see below), whose sum is σ = 28775424. Its totient is φ = 28728300.

The previous prime is 28751857. The next prime is 28751873. The reversal of 28751861 is 16815782.

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 28751861 - 2² = 28751857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28751851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9845 + ... + 12426.

It is an arithmetic number, because the mean of its divisors is an integer number (7193856).

Almost surely, 2^28751861 is an apocalyptic number.

It is an amenable number.

28751861 is a deficient number, since it is larger than the sum of its proper divisors (23563).

28751861 is a wasteful number, since it uses less digits than its factorization.

28751861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23562.

The product of its digits is 26880, while the sum is 38.

The square root of 28751861 is about 5362.0761837184. The cubic root of 28751861 is about 306.3528935949.

The spelling of 28751861 in words is "twenty-eight million, seven hundred fifty-one thousand, eight hundred sixty-one".