20390538 has 32 divisors (see below), whose sum is σ = 48216960. Its totient is φ = 5624640.

The previous prime is 20390483. The next prime is 20390549. The reversal of 20390538 is 83509302.

It is a happy number.

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 15 ways as a sum of consecutive naturals, for example, 7153 + ... + 9588.

It is an arithmetic number, because the mean of its divisors is an integer number (1506780).

Almost surely, 2^20390538 is an apocalyptic number.

20390538 is an abundant number, since it is smaller than the sum of its proper divisors (27826422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20390538 is a wasteful number, since it uses less digits than its factorization.

20390538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16782.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 20390538 is about 4515.5883337612. The cubic root of 20390538 is about 273.1971901156.

The spelling of 20390538 in words is "twenty million, three hundred ninety thousand, five hundred thirty-eight".