21891283793 has 4 divisors (see below), whose sum is σ = 22218019440. Its totient is φ = 21564548148.

The previous prime is 21891283787. The next prime is 21891283801. The reversal of 21891283793 is 39738219812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21891283793 - 2²⁶ = 21824174929 is a prime.

It is a super-2 number, since 2×21891283793² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21891283783) 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, 163367723 + ... + 163367856.

It is an arithmetic number, because the mean of its divisors is an integer number (5554504860).

Almost surely, 2^21891283793 is an apocalyptic number.

It is an amenable number.

21891283793 is a deficient number, since it is larger than the sum of its proper divisors (326735647).

21891283793 is an equidigital number, since it uses as much as digits as its factorization.

21891283793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326735646.

The product of its digits is 1306368, while the sum is 53.

The spelling of 21891283793 in words is "twenty-one billion, eight hundred ninety-one million, two hundred eighty-three thousand, seven hundred ninety-three".