31541036221 has 2 divisors, whose sum is σ = 31541036222. Its totient is φ = 31541036220.

The previous prime is 31541036209. The next prime is 31541036227. The reversal of 31541036221 is 12263014513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29065476196 + 2475560025 = 170486^2 + 49755^2 .

It is a cyclic number.

It is not a de Polignac number, because 31541036221 - 2³³ = 22951101629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31541036221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31541036227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770518110 + 15770518111.

It is an arithmetic number, because the mean of its divisors is an integer number (15770518111).

Almost surely, 2^31541036221 is an apocalyptic number.

It is an amenable number.

31541036221 is a deficient number, since it is larger than the sum of its proper divisors (1).

31541036221 is an equidigital number, since it uses as much as digits as its factorization.

31541036221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The spelling of 31541036221 in words is "thirty-one billion, five hundred forty-one million, thirty-six thousand, two hundred twenty-one".