21211218293 has 4 divisors (see below), whose sum is σ = 21266600448. Its totient is φ = 21155836140.

The previous prime is 21211218289. The next prime is 21211218313. The reversal of 21211218293 is 39281211212.

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 21211218293 - 2² = 21211218289 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211218283) 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, 27690503 + ... + 27691268.

It is an arithmetic number, because the mean of its divisors is an integer number (5316650112).

Almost surely, 2^21211218293 is an apocalyptic number.

It is an amenable number.

21211218293 is a deficient number, since it is larger than the sum of its proper divisors (55382155).

21211218293 is an equidigital number, since it uses as much as digits as its factorization.

21211218293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55382154.

The product of its digits is 3456, while the sum is 32.

The spelling of 21211218293 in words is "twenty-one billion, two hundred eleven million, two hundred eighteen thousand, two hundred ninety-three".