21123030231 has 40 divisors (see below), whose sum is σ = 31766662400. Its totient is φ = 13987527120.

The previous prime is 21123030211. The next prime is 21123030239. The reversal of 21123030231 is 13203032112.

It is not a de Polignac number, because 21123030231 - 2¹⁸ = 21122768087 is a prime.

It is a super-2 number, since 2×21123030231² (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 (21123030239) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8318160 + ... + 8320698.

It is an arithmetic number, because the mean of its divisors is an integer number (794166560).

Almost surely, 2^21123030231 is an apocalyptic number.

21123030231 is a deficient number, since it is larger than the sum of its proper divisors (10643632169).

21123030231 is a wasteful number, since it uses less digits than its factorization.

21123030231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3201 (or 3192 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21123030231 its reverse (13203032112), we get a palindrome (34326062343).

The spelling of 21123030231 in words is "twenty-one billion, one hundred twenty-three million, thirty thousand, two hundred thirty-one".