20388290 has 16 divisors (see below), whose sum is σ = 39522168. Its totient is φ = 7527936.

The previous prime is 20388283. The next prime is 20388307. The reversal of 20388290 is 9288302.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9504889 + 10883401 = 3083^2 + 3299^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78287 + ... + 78546.

Almost surely, 2^20388290 is an apocalyptic number.

20388290 is a deficient number, since it is larger than the sum of its proper divisors (19133878).

20388290 is a wasteful number, since it uses less digits than its factorization.

20388290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156853.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 20388290 is about 4515.3394113843. The cubic root of 20388290 is about 273.1871500037.

The spelling of 20388290 in words is "twenty million, three hundred eighty-eight thousand, two hundred ninety".