20970664 has 64 divisors (see below), whose sum is σ = 48263040. Its totient is φ = 8405760.

The previous prime is 20970643. The next prime is 20970667. The reversal of 20970664 is 46607902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20970667) 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, 25914 + ... + 26710.

It is an arithmetic number, because the mean of its divisors is an integer number (754110).

Almost surely, 2^20970664 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 20970664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24131520).

20970664 is an abundant number, since it is smaller than the sum of its proper divisors (27292376).

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

20970664 is a wasteful number, since it uses less digits than its factorization.

20970664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850 (or 846 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 20970664 is about 4579.3737563121. The cubic root of 20970664 is about 275.7638882465.

The spelling of 20970664 in words is "twenty million, nine hundred seventy thousand, six hundred sixty-four".