21231431069 has 2 divisors, whose sum is σ = 21231431070. Its totient is φ = 21231431068.

The previous prime is 21231431029. The next prime is 21231431093. The reversal of 21231431069 is 96013413212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17812105444 + 3419325625 = 133462^2 + 58475^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231431069 - 2²⁴ = 21214653853 is a prime.

It is a super-2 number, since 2×21231431069² (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 (21231431009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615715534 + 10615715535.

It is an arithmetic number, because the mean of its divisors is an integer number (10615715535).

Almost surely, 2^21231431069 is an apocalyptic number.

It is an amenable number.

21231431069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231431069 is an equidigital number, since it uses as much as digits as its factorization.

21231431069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 32.

It can be divided in two parts, 2123143 and 1069, that added together give a palindrome (2124212).

The spelling of 21231431069 in words is "twenty-one billion, two hundred thirty-one million, four hundred thirty-one thousand, sixty-nine".