20889780 has 24 divisors (see below), whose sum is σ = 58491552. Its totient is φ = 5570592.

The previous prime is 20889779. The next prime is 20889809. The reversal of 20889780 is 8798802.

It is a happy number.

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, 174022 + ... + 174141.

It is an arithmetic number, because the mean of its divisors is an integer number (2437148).

Almost surely, 2^20889780 is an apocalyptic number.

20889780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20889780 is an abundant number, since it is smaller than the sum of its proper divisors (37601772).

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

20889780 is a wasteful number, since it uses less digits than its factorization.

20889780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348175 (or 348173 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 20889780 is about 4570.5338856637. The cubic root of 20889780 is about 275.4088903528.

The spelling of 20889780 in words is "twenty million, eight hundred eighty-nine thousand, seven hundred eighty".