21497049863 has 4 divisors (see below), whose sum is σ = 22628473560. Its totient is φ = 20365626168.

The previous prime is 21497049793. The next prime is 21497049911. The reversal of 21497049863 is 36894079412.

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 21497049863 - 2²⁰ = 21496001287 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 (21497049163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 565711820 + ... + 565711857.

It is an arithmetic number, because the mean of its divisors is an integer number (5657118390).

Almost surely, 2^21497049863 is an apocalyptic number.

21497049863 is a deficient number, since it is larger than the sum of its proper divisors (1131423697).

21497049863 is a wasteful number, since it uses less digits than its factorization.

21497049863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1131423696.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The spelling of 21497049863 in words is "twenty-one billion, four hundred ninety-seven million, forty-nine thousand, eight hundred sixty-three".