20309980 has 12 divisors (see below), whose sum is σ = 42651000. Its totient is φ = 8123984.

The previous prime is 20309959. The next prime is 20309999. The reversal of 20309980 is 8990302.

It is a happy number.

It is a super-3 number, since 3×20309980³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 507730 + ... + 507769.

It is an arithmetic number, because the mean of its divisors is an integer number (3554250).

Almost surely, 2^20309980 is an apocalyptic number.

20309980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20309980 is an abundant number, since it is smaller than the sum of its proper divisors (22341020).

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

20309980 is a wasteful number, since it uses less digits than its factorization.

20309980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015508 (or 1015506 counting only the distinct ones).

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

The square root of 20309980 is about 4506.6595167596. The cubic root of 20309980 is about 272.8369369753.

The spelling of 20309980 in words is "twenty million, three hundred nine thousand, nine hundred eighty".