20980890 has 128 divisors (see below), whose sum is σ = 67806720. Its totient is φ = 4506624.

The previous prime is 20980879. The next prime is 20980901. The reversal of 20980890 is 9808902.

It is an interprime number because it is at equal distance from previous prime (20980879) and next prime (20980901).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 31804 + ... + 32456.

It is an arithmetic number, because the mean of its divisors is an integer number (529740).

Almost surely, 2^20980890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20980890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33903360).

20980890 is an abundant number, since it is smaller than the sum of its proper divisors (46825830).

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

20980890 is a wasteful number, since it uses less digits than its factorization.

20980890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 20980890 is about 4580.4901484448. The cubic root of 20980890 is about 275.8087048734.

The spelling of 20980890 in words is "twenty million, nine hundred eighty thousand, eight hundred ninety".