20249720 has 64 divisors (see below), whose sum is σ = 48898080. Its totient is φ = 7520256.

The previous prime is 20249717. The next prime is 20249731. The reversal of 20249720 is 2794202.

It is a self number, because there is not a number n which added to its sum of digits gives 20249720.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65807 + ... + 66113.

Almost surely, 2^20249720 is an apocalyptic number.

20249720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20249720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24449040).

20249720 is an abundant number, since it is smaller than the sum of its proper divisors (28648360).

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

20249720 is a wasteful number, since it uses less digits than its factorization.

20249720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 20249720 is about 4499.9688887813. The cubic root of 20249720 is about 272.5668326381.

The spelling of 20249720 in words is "twenty million, two hundred forty-nine thousand, seven hundred twenty".