20922990 has 128 divisors (see below), whose sum is σ = 59719680. Its totient is φ = 4636800.

The previous prime is 20922973. The next prime is 20922991. The reversal of 20922990 is 9922902.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20922991) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 294655 + ... + 294725.

It is an arithmetic number, because the mean of its divisors is an integer number (466560).

Almost surely, 2^20922990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20922990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29859840).

20922990 is an abundant number, since it is smaller than the sum of its proper divisors (38796690).

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

20922990 is a wasteful number, since it uses less digits than its factorization.

20922990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 20922990 is about 4574.1654976618. The cubic root of 20922990 is about 275.5547589173.

It can be divided in two parts, 20922 and 990, that added together give a palindrome (21912).

The spelling of 20922990 in words is "twenty million, nine hundred twenty-two thousand, nine hundred ninety".