20724090 has 32 divisors (see below), whose sum is σ = 49934016. Its totient is φ = 5504640.

The previous prime is 20724049. The next prime is 20724091. The reversal of 20724090 is 9042702.

It is a self number, because there is not a number n which added to its sum of digits gives 20724090.

It is not an unprimeable number, because it can be changed into a prime (20724091) 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, 7270 + ... + 9710.

It is an arithmetic number, because the mean of its divisors is an integer number (1560438).

Almost surely, 2^20724090 is an apocalyptic number.

20724090 is an abundant number, since it is smaller than the sum of its proper divisors (29209926).

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

20724090 is a wasteful number, since it uses less digits than its factorization.

20724090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2734.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 20724090 is about 4552.3719092359. The cubic root of 20724090 is about 274.6788095798.

Adding to 20724090 its reverse (9042702), we get a palindrome (29766792).

The spelling of 20724090 in words is "twenty million, seven hundred twenty-four thousand, ninety".