20431590 has 32 divisors (see below), whose sum is σ = 51169536. Its totient is φ = 5211360.

The previous prime is 20431577. The next prime is 20431591. The reversal of 20431590 is 9513402.

It is a self number, because there is not a number n which added to its sum of digits gives 20431590.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431591) 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, 14116 + ... + 15495.

It is an arithmetic number, because the mean of its divisors is an integer number (1599048).

Almost surely, 2^20431590 is an apocalyptic number.

20431590 is an abundant number, since it is smaller than the sum of its proper divisors (30737946).

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

20431590 is a wasteful number, since it uses less digits than its factorization.

20431590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29644.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20431590 is about 4520.1316352513. The cubic root of 20431590 is about 273.3804086412.

Adding to 20431590 its reverse (9513402), we get a palindrome (29944992).

The spelling of 20431590 in words is "twenty million, four hundred thirty-one thousand, five hundred ninety".