28404657 has 6 divisors (see below), whose sum is σ = 41028962. Its totient is φ = 18936432.

The previous prime is 28404613. The next prime is 28404679. The reversal of 28404657 is 75640482.

It can be written as a sum of positive squares in only one way, i.e., 28291761 + 112896 = 5319^2 + 336^2 .

It is not a de Polignac number, because 28404657 - 2¹⁰ = 28403633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28404457) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1578028 + ... + 1578045.

Almost surely, 2^28404657 is an apocalyptic number.

It is an amenable number.

28404657 is a deficient number, since it is larger than the sum of its proper divisors (12624305).

28404657 is a wasteful number, since it uses less digits than its factorization.

28404657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3156079 (or 3156076 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 28404657 is about 5329.6019551182. The cubic root of 28404657 is about 305.1147360140.

The spelling of 28404657 in words is "twenty-eight million, four hundred four thousand, six hundred fifty-seven".