20724420 has 48 divisors (see below), whose sum is σ = 58339008. Its totient is φ = 5496960.

The previous prime is 20724397. The next prime is 20724427. The reversal of 20724420 is 2442702.

It is not an unprimeable number, because it can be changed into a prime (20724427) 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, 11842 + ... + 13478.

It is an arithmetic number, because the mean of its divisors is an integer number (1215396).

Almost surely, 2^20724420 is an apocalyptic number.

20724420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20724420 is an abundant number, since it is smaller than the sum of its proper divisors (37614588).

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

20724420 is a wasteful number, since it uses less digits than its factorization.

20724420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860 (or 1858 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 21.

The square root of 20724420 is about 4552.4081539335. The cubic root of 20724420 is about 274.6802675212.

The spelling of 20724420 in words is "twenty million, seven hundred twenty-four thousand, four hundred twenty".