20970890 has 16 divisors (see below), whose sum is σ = 37837800. Its totient is φ = 8368320.

The previous prime is 20970869. The next prime is 20970893. The reversal of 20970890 is 9807902.

It can be written as a sum of positive squares in 4 ways, for example, as 17280649 + 3690241 = 4157^2 + 1921^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20970890.

It is not an unprimeable number, because it can be changed into a prime (20970893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2336 + ... + 6884.

Almost surely, 2^20970890 is an apocalyptic number.

20970890 is a deficient number, since it is larger than the sum of its proper divisors (16866910).

20970890 is a wasteful number, since it uses less digits than its factorization.

20970890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5017.

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

The square root of 20970890 is about 4579.3984321087. The cubic root of 20970890 is about 275.7648788750.

The spelling of 20970890 in words is "twenty million, nine hundred seventy thousand, eight hundred ninety".