21121210231 has 8 divisors (see below), whose sum is σ = 23356955664. Its totient is φ = 18938070720.

The previous prime is 21121210171. The next prime is 21121210237. The reversal of 21121210231 is 13201212112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21121210231 - 2⁹ = 21121209719 is a prime.

It is a super-2 number, since 2×21121210231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121210237) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13150636 + ... + 13152241.

It is an arithmetic number, because the mean of its divisors is an integer number (2919619458).

Almost surely, 2^21121210231 is an apocalyptic number.

21121210231 is a deficient number, since it is larger than the sum of its proper divisors (2235745433).

21121210231 is a wasteful number, since it uses less digits than its factorization.

21121210231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26302961.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21121210231 its reverse (13201212112), we get a palindrome (34322422343).

The spelling of 21121210231 in words is "twenty-one billion, one hundred twenty-one million, two hundred ten thousand, two hundred thirty-one".