20749220 has 48 divisors (see below), whose sum is σ = 46569600. Its totient is φ = 7746816.

The previous prime is 20749213. The next prime is 20749229. The reversal of 20749220 is 2294702.

It is a self number, because there is not a number n which added to its sum of digits gives 20749220.

It is not an unprimeable number, because it can be changed into a prime (20749229) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 19256 + ... + 20304.

It is an arithmetic number, because the mean of its divisors is an integer number (970200).

Almost surely, 2^20749220 is an apocalyptic number.

20749220 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 20749220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23284800).

20749220 is an abundant number, since it is smaller than the sum of its proper divisors (25820380).

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

20749220 is a wasteful number, since it uses less digits than its factorization.

20749220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124 (or 1122 counting only the distinct ones).

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

The square root of 20749220 is about 4555.1311726448. The cubic root of 20749220 is about 274.7897897693.

The spelling of 20749220 in words is "twenty million, seven hundred forty-nine thousand, two hundred twenty".