21796203857 has 4 divisors (see below), whose sum is σ = 21996169140. Its totient is φ = 21596238576.

The previous prime is 21796203841. The next prime is 21796203887. The reversal of 21796203857 is 75830269712.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5231484241 + 16564719616 = 72329^2 + 128704^2 .

It is a cyclic number.

It is not a de Polignac number, because 21796203857 - 2⁴ = 21796203841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21796203817) 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 3 ways as a sum of consecutive naturals, for example, 99982478 + ... + 99982695.

It is an arithmetic number, because the mean of its divisors is an integer number (5499042285).

Almost surely, 2^21796203857 is an apocalyptic number.

It is an amenable number.

21796203857 is a deficient number, since it is larger than the sum of its proper divisors (199965283).

21796203857 is a wasteful number, since it uses less digits than its factorization.

21796203857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199965282.

The product of its (nonzero) digits is 1270080, while the sum is 50.

The spelling of 21796203857 in words is "twenty-one billion, seven hundred ninety-six million, two hundred three thousand, eight hundred fifty-seven".