20845980 has 36 divisors (see below), whose sum is σ = 63233352. Its totient is φ = 5558880.

The previous prime is 20845963. The next prime is 20845991. The reversal of 20845980 is 8954802.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57726 + ... + 58085.

It is an arithmetic number, because the mean of its divisors is an integer number (1756482).

Almost surely, 2^20845980 is an apocalyptic number.

20845980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20845980 is an abundant number, since it is smaller than the sum of its proper divisors (42387372).

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

20845980 is a wasteful number, since it uses less digits than its factorization.

20845980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115826 (or 115821 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 20845980 is about 4565.7398086181. The cubic root of 20845980 is about 275.2162706432.

The spelling of 20845980 in words is "twenty million, eight hundred forty-five thousand, nine hundred eighty".