28661247 has 12 divisors (see below), whose sum is σ = 41584920. Its totient is φ = 19021968.

The previous prime is 28661221. The next prime is 28661257. The reversal of 28661247 is 74216682.

It is not a de Polignac number, because 28661247 - 2⁶ = 28661183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28661257) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4972 + ... + 9057.

It is an arithmetic number, because the mean of its divisors is an integer number (3465410).

Almost surely, 2^28661247 is an apocalyptic number.

28661247 is a deficient number, since it is larger than the sum of its proper divisors (12923673).

28661247 is a wasteful number, since it uses less digits than its factorization.

28661247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14262 (or 14259 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 28661247 is about 5353.6199902496. The cubic root of 28661247 is about 306.0307222774.

It can be divided in two parts, 2 and 8661247, that added together give a square (8661249 = 2943²).

The spelling of 28661247 in words is "twenty-eight million, six hundred sixty-one thousand, two hundred forty-seven".