20531538 has 24 divisors (see below), whose sum is σ = 44568576. Its totient is φ = 6831000.

The previous prime is 20531521. The next prime is 20531543. The reversal of 20531538 is 83513502.

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 11 ways as a sum of consecutive naturals, for example, 17263 + ... + 18413.

It is an arithmetic number, because the mean of its divisors is an integer number (1857024).

Almost surely, 2^20531538 is an apocalyptic number.

20531538 is an abundant number, since it is smaller than the sum of its proper divisors (24037038).

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

20531538 is a wasteful number, since it uses less digits than its factorization.

20531538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2150 (or 2147 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 20531538 is about 4531.1740200526. The cubic root of 20531538 is about 273.8254611508.

The spelling of 20531538 in words is "twenty million, five hundred thirty-one thousand, five hundred thirty-eight".