20309880 has 32 divisors (see below), whose sum is σ = 60930000. Its totient is φ = 5415936.

The previous prime is 20309869. The next prime is 20309893. The reversal of 20309880 is 8890302.

It is a super-2 number, since 2×20309880² = 824982451228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84505 + ... + 84744.

Almost surely, 2^20309880 is an apocalyptic number.

20309880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20309880 is an abundant number, since it is smaller than the sum of its proper divisors (40620120).

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

20309880 is a wasteful number, since it uses less digits than its factorization.

20309880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169263 (or 169259 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 20309880 is about 4506.6484220538. The cubic root of 20309880 is about 272.8364891866.

The spelling of 20309880 in words is "twenty million, three hundred nine thousand, eight hundred eighty".