20995919999 has 4 divisors (see below), whose sum is σ = 22100968440. Its totient is φ = 19890871560.

The previous prime is 20995919977. The next prime is 20995920007. The reversal of 20995919999 is 99991959902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20995919999 - 2²⁰ = 20994871423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20995919929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552524192 + ... + 552524229.

It is an arithmetic number, because the mean of its divisors is an integer number (5525242110).

Almost surely, 2^20995919999 is an apocalyptic number.

20995919999 is a deficient number, since it is larger than the sum of its proper divisors (1105048441).

20995919999 is a wasteful number, since it uses less digits than its factorization.

20995919999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105048440.

The product of its (nonzero) digits is 47829690, while the sum is 71.

The spelling of 20995919999 in words is "twenty billion, nine hundred ninety-five million, nine hundred nineteen thousand, nine hundred ninety-nine".