20422864 has 80 divisors (see below), whose sum is σ = 50103936. Its totient is φ = 7898880.

The previous prime is 20422859. The next prime is 20422867. The reversal of 20422864 is 46822402.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20422867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149004 + ... + 149140.

Almost surely, 2^20422864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20422864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25051968).

20422864 is an abundant number, since it is smaller than the sum of its proper divisors (29681072).

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

20422864 is a wasteful number, since it uses less digits than its factorization.

20422864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 28.

The square root of 20422864 is about 4519.1662947938. The cubic root of 20422864 is about 273.3414843230.

The spelling of 20422864 in words is "twenty million, four hundred twenty-two thousand, eight hundred sixty-four".