20431764 has 60 divisors (see below), whose sum is σ = 56240800. Its totient is φ = 6450192.

The previous prime is 20431753. The next prime is 20431777. The reversal of 20431764 is 46713402.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4497 + ... + 7815.

Almost surely, 2^20431764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20431764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28120400).

20431764 is an abundant number, since it is smaller than the sum of its proper divisors (35809036).

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

20431764 is a wasteful number, since it uses less digits than its factorization.

20431764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3354 (or 3343 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 20431764 is about 4520.1508824374. The cubic root of 20431764 is about 273.3811846953.

The spelling of 20431764 in words is "twenty million, four hundred thirty-one thousand, seven hundred sixty-four".