20889870 has 32 divisors (see below), whose sum is σ = 50319360. Its totient is φ = 5550240.

The previous prime is 20889859. The next prime is 20889871. The reversal of 20889870 is 7898802.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20889871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8211 + ... + 10449.

It is an arithmetic number, because the mean of its divisors is an integer number (1572480).

Almost surely, 2^20889870 is an apocalyptic number.

20889870 is the 3732-nd pentagonal number.

20889870 is an abundant number, since it is smaller than the sum of its proper divisors (29429490).

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

20889870 is a wasteful number, since it uses less digits than its factorization.

20889870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560.

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

The square root of 20889870 is about 4570.5437313300. The cubic root of 20889870 is about 275.4092858694.

The spelling of 20889870 in words is "twenty million, eight hundred eighty-nine thousand, eight hundred seventy".