20209512961 has 8 divisors (see below), whose sum is σ = 22642599744. Its totient is φ = 17875735920.

The previous prime is 20209512959. The next prime is 20209512989. The reversal of 20209512961 is 16921590202.

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

It is a cyclic number.

It is not a de Polignac number, because 20209512961 - 2¹ = 20209512959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20209512961.

It is not an unprimeable number, because it can be changed into a prime (20209522961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24827005 + ... + 24827818.

It is an arithmetic number, because the mean of its divisors is an integer number (2830324968).

Almost surely, 2^20209512961 is an apocalyptic number.

It is an amenable number.

20209512961 is a deficient number, since it is larger than the sum of its proper divisors (2433086783).

20209512961 is a wasteful number, since it uses less digits than its factorization.

20209512961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49654871.

The product of its (nonzero) digits is 19440, while the sum is 37.

The spelling of 20209512961 in words is "twenty billion, two hundred nine million, five hundred twelve thousand, nine hundred sixty-one".