28156797 has 6 divisors (see below), whose sum is σ = 40670942. Its totient is φ = 18771192.

The previous prime is 28156781. The next prime is 28156823. The reversal of 28156797 is 79765182.

28156797 is a `hidden beast` number, since 2 + 81 + 567 + 9 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16088121 + 12068676 = 4011^2 + 3474^2 .

It is not a de Polignac number, because 28156797 - 2⁴ = 28156781 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 (28156717) 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, 1564258 + ... + 1564275.

Almost surely, 2^28156797 is an apocalyptic number.

It is an amenable number.

28156797 is a deficient number, since it is larger than the sum of its proper divisors (12514145).

28156797 is a wasteful number, since it uses less digits than its factorization.

28156797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128539 (or 3128536 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 28156797 is about 5306.2978619750. The cubic root of 28156797 is about 304.2246615213.

The spelling of 28156797 in words is "twenty-eight million, one hundred fifty-six thousand, seven hundred ninety-seven".