20530890 has 48 divisors (see below), whose sum is σ = 53757288. Its totient is φ = 5436288.

The previous prime is 20530889. The next prime is 20530891. The reversal of 20530890 is 9803502.

It is an interprime number because it is at equal distance from previous prime (20530889) and next prime (20530891).

It can be written as a sum of positive squares in 4 ways, for example, as 19210689 + 1320201 = 4383^2 + 1149^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20530891) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13404 + ... + 14856.

Almost surely, 2^20530890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20530890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26878644).

20530890 is an abundant number, since it is smaller than the sum of its proper divisors (33226398).

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

20530890 is a wasteful number, since it uses less digits than its factorization.

20530890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1623 (or 1620 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20530890 is about 4531.1025148412. The cubic root of 20530890 is about 273.8225803670.

The spelling of 20530890 in words is "twenty million, five hundred thirty thousand, eight hundred ninety".