21013001231 has 2 divisors, whose sum is σ = 21013001232. Its totient is φ = 21013001230.

The previous prime is 21013001201. The next prime is 21013001267. The reversal of 21013001231 is 13210031012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21013001231 - 2¹⁴ = 21012984847 is a prime.

It is a super-2 number, since 2×21013001231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013001201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506500615 + 10506500616.

It is an arithmetic number, because the mean of its divisors is an integer number (10506500616).

Almost surely, 2^21013001231 is an apocalyptic number.

21013001231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013001231 is an equidigital number, since it uses as much as digits as its factorization.

21013001231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21013001231 its reverse (13210031012), we get a palindrome (34223032243).

The spelling of 21013001231 in words is "twenty-one billion, thirteen million, one thousand, two hundred thirty-one".