20281980 has 24 divisors (see below), whose sum is σ = 56789712. Its totient is φ = 5408512.

The previous prime is 20281973. The next prime is 20281993. The reversal of 20281980 is 8918202.

It is a super-2 number, since 2×20281980² = 822717425440800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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, 168957 + ... + 169076.

It is an arithmetic number, because the mean of its divisors is an integer number (2366238).

Almost surely, 2^20281980 is an apocalyptic number.

20281980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20281980 is an abundant number, since it is smaller than the sum of its proper divisors (36507732).

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

20281980 is a wasteful number, since it uses less digits than its factorization.

20281980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338045 (or 338043 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 20281980 is about 4503.5519315314. The cubic root of 20281980 is about 272.7114986836.

The spelling of 20281980 in words is "twenty million, two hundred eighty-one thousand, nine hundred eighty".