20820704690 has 24 divisors (see below), whose sum is σ = 39177570348. Its totient is φ = 7966180640.

The previous prime is 20820704689. The next prime is 20820704701. The reversal of 20820704690 is 9640702802.

It can be written as a sum of positive squares in 2 ways, for example, as 19420373449 + 1400331241 = 139357^2 + 37421^2 .

It is a super-2 number, since 2×20820704690² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1962641 + ... + 1973220.

Almost surely, 2^20820704690 is an apocalyptic number.

20820704690 is a deficient number, since it is larger than the sum of its proper divisors (18356865658).

20820704690 is a wasteful number, since it uses less digits than its factorization.

20820704690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3935914 (or 3935891 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 38.

The spelling of 20820704690 in words is "twenty billion, eight hundred twenty million, seven hundred four thousand, six hundred ninety".