31211130421 has 2 divisors, whose sum is σ = 31211130422. Its totient is φ = 31211130420.

The previous prime is 31211130361. The next prime is 31211130427. The reversal of 31211130421 is 12403111213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30874004100 + 337126321 = 175710^2 + 18361^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31211130421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31211130427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15605565210 + 15605565211.

It is an arithmetic number, because the mean of its divisors is an integer number (15605565211).

Almost surely, 2^31211130421 is an apocalyptic number.

It is an amenable number.

31211130421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31211130421 is an equidigital number, since it uses as much as digits as its factorization.

31211130421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 31211130421 its reverse (12403111213), we get a palindrome (43614241634).

The spelling of 31211130421 in words is "thirty-one billion, two hundred eleven million, one hundred thirty thousand, four hundred twenty-one".