28515987 has 12 divisors (see below), whose sum is σ = 43612920. Its totient is φ = 17892288.

The previous prime is 28515983. The next prime is 28515997. The reversal of 28515987 is 78951582.

It is a happy number.

28515987 is a `hidden beast` number, since 2 + 8 + 51 + 598 + 7 = 666.

It is not a de Polignac number, because 28515987 - 2² = 28515983 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28515983) 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, 93037 + ... + 93342.

It is an arithmetic number, because the mean of its divisors is an integer number (3634410).

Almost surely, 2^28515987 is an apocalyptic number.

28515987 is a deficient number, since it is larger than the sum of its proper divisors (15096933).

28515987 is a wasteful number, since it uses less digits than its factorization.

28515987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186402 (or 186399 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The square root of 28515987 is about 5340.0362358321. The cubic root of 28515987 is about 305.5128414023.

The spelling of 28515987 in words is "twenty-eight million, five hundred fifteen thousand, nine hundred eighty-seven".