28990018 has 8 divisors (see below), whose sum is σ = 44660412. Its totient is φ = 14103216.

The previous prime is 28990009. The next prime is 28990019. The reversal of 28990018 is 81009982.

It can be written as a sum of positive squares in 2 ways, for example, as 28376929 + 613089 = 5327^2 + 783^2 .

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

It is a super-2 number, since 2×28990018² = 1680842287280648, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is not an unprimeable number, because it can be changed into a prime (28990019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195805 + ... + 195952.

Almost surely, 2^28990018 is an apocalyptic number.

28990018 is a deficient number, since it is larger than the sum of its proper divisors (15670394).

28990018 is a wasteful number, since it uses less digits than its factorization.

28990018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391796.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 28990018 is about 5384.2379219347. The cubic root of 28990018 is about 307.1964281020.

The spelling of 28990018 in words is "twenty-eight million, nine hundred ninety thousand, eighteen".