28390690 has 8 divisors (see below), whose sum is σ = 51103260. Its totient is φ = 11356272.

The previous prime is 28390673. The next prime is 28390721. The reversal of 28390690 is 9609382.

It can be written as a sum of positive squares in 2 ways, for example, as 28185481 + 205209 = 5309^2 + 453^2 .

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

It is a super-2 number, since 2×28390690² = 1612062557352200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1419525 + ... + 1419544.

Almost surely, 2^28390690 is an apocalyptic number.

28390690 is a deficient number, since it is larger than the sum of its proper divisors (22712570).

28390690 is a wasteful number, since it uses less digits than its factorization.

28390690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839076.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 28390690 is about 5328.2914710064. The cubic root of 28390690 is about 305.0647179695.

The spelling of 28390690 in words is "twenty-eight million, three hundred ninety thousand, six hundred ninety".