20909380 has 12 divisors (see below), whose sum is σ = 43909740. Its totient is φ = 8363744.

The previous prime is 20909363. The next prime is 20909381. The reversal of 20909380 is 8390902.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10137856 + 10771524 = 3184^2 + 3282^2 .

It is not an unprimeable number, because it can be changed into a prime (20909381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 522715 + ... + 522754.

It is an arithmetic number, because the mean of its divisors is an integer number (3659145).

Almost surely, 2^20909380 is an apocalyptic number.

20909380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20909380 is an abundant number, since it is smaller than the sum of its proper divisors (23000360).

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

20909380 is a wasteful number, since it uses less digits than its factorization.

20909380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1045478 (or 1045476 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 20909380 is about 4572.6775525943. The cubic root of 20909380 is about 275.4949982788.

The spelling of 20909380 in words is "twenty million, nine hundred nine thousand, three hundred eighty".