20309538 has 16 divisors (see below), whose sum is σ = 40864320. Its totient is φ = 6728976.

The previous prime is 20309507. The next prime is 20309551. The reversal of 20309538 is 83590302.

It is a happy number.

It is a Curzon number.

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, 9133 + ... + 11136.

It is an arithmetic number, because the mean of its divisors is an integer number (2554020).

Almost surely, 2^20309538 is an apocalyptic number.

20309538 is an abundant number, since it is smaller than the sum of its proper divisors (20554782).

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

20309538 is a wasteful number, since it uses less digits than its factorization.

20309538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20441.

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

The square root of 20309538 is about 4506.6104779535. The cubic root of 20309538 is about 272.8349577381.

The spelling of 20309538 in words is "twenty million, three hundred nine thousand, five hundred thirty-eight".