21242331291 has 4 divisors (see below), whose sum is σ = 28323108392. Its totient is φ = 14161554192.

The previous prime is 21242331287. The next prime is 21242331301. The reversal of 21242331291 is 19213324212.

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

It is not a de Polignac number, because 21242331291 - 2² = 21242331287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21242331241) 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, 3540388546 + ... + 3540388551.

It is an arithmetic number, because the mean of its divisors is an integer number (7080777098).

Almost surely, 2^21242331291 is an apocalyptic number.

21242331291 is a deficient number, since it is larger than the sum of its proper divisors (7080777101).

21242331291 is an equidigital number, since it uses as much as digits as its factorization.

21242331291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7080777100.

The product of its digits is 5184, while the sum is 30.

The spelling of 21242331291 in words is "twenty-one billion, two hundred forty-two million, three hundred thirty-one thousand, two hundred ninety-one".