20138523 has 16 divisors (see below), whose sum is σ = 28532736. Its totient is φ = 12590720.

The previous prime is 20138507. The next prime is 20138527. The reversal of 20138523 is 32583102.

It is a cyclic number.

It is not a de Polignac number, because 20138523 - 2⁴ = 20138507 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20138493 and 20138502.

It is not an unprimeable number, because it can be changed into a prime (20138527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19018 + ... + 20048.

It is an arithmetic number, because the mean of its divisors is an integer number (1783296).

Almost surely, 2^20138523 is an apocalyptic number.

20138523 is a deficient number, since it is larger than the sum of its proper divisors (8394213).

20138523 is a wasteful number, since it uses less digits than its factorization.

20138523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 20138523 is about 4487.5965727770. The cubic root of 20138523 is about 272.0670024888.

The spelling of 20138523 in words is "twenty million, one hundred thirty-eight thousand, five hundred twenty-three".