20890970 has 16 divisors (see below), whose sum is σ = 38027880. Its totient is φ = 8262144.

The previous prime is 20890949. The next prime is 20890979. The reversal of 20890970 is 7909802.

It can be written as a sum of positive squares in 4 ways, for example, as 19193161 + 1697809 = 4381^2 + 1303^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20890970.

It is not an unprimeable number, because it can be changed into a prime (20890979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10847 + ... + 12626.

Almost surely, 2^20890970 is an apocalyptic number.

20890970 is a deficient number, since it is larger than the sum of its proper divisors (17136910).

20890970 is a wasteful number, since it uses less digits than its factorization.

20890970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23569.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 20890970 is about 4570.6640655380. The cubic root of 20890970 is about 275.4141198695.

The spelling of 20890970 in words is "twenty million, eight hundred ninety thousand, nine hundred seventy".