28666731 has 8 divisors (see below), whose sum is σ = 38345680. Its totient is φ = 19049472.

The previous prime is 28666727. The next prime is 28666733. The reversal of 28666731 is 13766682.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28666731 - 2² = 28666727 is a prime.

It is a super-2 number, since 2×28666731² = 1643562932452722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28666731.

It is not an unprimeable number, because it can be changed into a prime (28666733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14326 + ... + 16203.

It is an arithmetic number, because the mean of its divisors is an integer number (4793210).

Almost surely, 2^28666731 is an apocalyptic number.

28666731 is a deficient number, since it is larger than the sum of its proper divisors (9678949).

28666731 is a wasteful number, since it uses less digits than its factorization.

28666731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30845.

The product of its digits is 72576, while the sum is 39.

The square root of 28666731 is about 5354.1321425605. The cubic root of 28666731 is about 306.0502395191.

The spelling of 28666731 in words is "twenty-eight million, six hundred sixty-six thousand, seven hundred thirty-one".