28660731 has 16 divisors (see below), whose sum is σ = 41793408. Its totient is φ = 17326400.

The previous prime is 28660727. The next prime is 28660733. The reversal of 28660731 is 13706682.

It is a cyclic number.

It is not a de Polignac number, because 28660731 - 2² = 28660727 is a prime.

It is a super-2 number, since 2×28660731² = 1642875002908722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 28660692 and 28660701.

It is not an unprimeable number, because it can be changed into a prime (28660733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16360 + ... + 18026.

It is an arithmetic number, because the mean of its divisors is an integer number (2612088).

Almost surely, 2^28660731 is an apocalyptic number.

28660731 is a deficient number, since it is larger than the sum of its proper divisors (13132677).

28660731 is a wasteful number, since it uses less digits than its factorization.

28660731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2202.

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 28660731 is about 5353.5717983417. The cubic root of 28660731 is about 306.0288857349.

The spelling of 28660731 in words is "twenty-eight million, six hundred sixty thousand, seven hundred thirty-one".