20207664 has 80 divisors (see below), whose sum is σ = 60040800. Its totient is φ = 6499584.

The previous prime is 20207651. The next prime is 20207683. The reversal of 20207664 is 46670202.

It is a hoax number, since the sum of its digits (27) 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 (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11722 + ... + 13334.

It is an arithmetic number, because the mean of its divisors is an integer number (750510).

Almost surely, 2^20207664 is an apocalyptic number.

20207664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20207664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30020400).

20207664 is an abundant number, since it is smaller than the sum of its proper divisors (39833136).

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

20207664 is a wasteful number, since it uses less digits than its factorization.

20207664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659 (or 1647 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 20207664 is about 4495.2935388026. The cubic root of 20207664 is about 272.3780067244.

Adding to 20207664 its reverse (46670202), we get a palindrome (66877866).

The spelling of 20207664 in words is "twenty million, two hundred seven thousand, six hundred sixty-four".