20280690 has 24 divisors (see below), whose sum is σ = 52730028. Its totient is φ = 5408160.

The previous prime is 20280683. The next prime is 20280707. The reversal of 20280690 is 9608202.

It can be written as a sum of positive squares in 2 ways, for example, as 16719921 + 3560769 = 4089^2 + 1887^2 .

It is a super-2 number, since 2×20280690² = 822612773752200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112581 + ... + 112760.

Almost surely, 2^20280690 is an apocalyptic number.

20280690 is an abundant number, since it is smaller than the sum of its proper divisors (32449338).

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

20280690 is a wasteful number, since it uses less digits than its factorization.

20280690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225354 (or 225351 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20280690 is about 4503.4087089670. The cubic root of 20280690 is about 272.7057167811.

Adding to 20280690 its reverse (9608202), we get a palindrome (29888892).

The spelling of 20280690 in words is "twenty million, two hundred eighty thousand, six hundred ninety".