20995385986 has 8 divisors (see below), whose sum is σ = 31493847420. Its totient is φ = 10497436848.

The previous prime is 20995385977. The next prime is 20995385993. The reversal of 20995385986 is 68958359902.

20995385986 is a nontrivial binomial coefficient, being equal to C(204917, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 19885230225 + 1110155761 = 141015^2 + 33319^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20995385986² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 204916.

Almost surely, 2^20995385986 is an apocalyptic number.

20995385986 is the 204916-th triangular number.

20995385986 is the 68306-th centered nonagonal number.

20995385986 is a deficient number, since it is larger than the sum of its proper divisors (10498461434).

20995385986 is a wasteful number, since it uses less digits than its factorization.

20995385986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256148.

The product of its (nonzero) digits is 41990400, while the sum is 64.

The spelling of 20995385986 in words is "twenty billion, nine hundred ninety-five million, three hundred eighty-five thousand, nine hundred eighty-six".