31261033261 has 2 divisors, whose sum is σ = 31261033262. Its totient is φ = 31261033260.

The previous prime is 31261033259. The next prime is 31261033273. The reversal of 31261033261 is 16233016213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22460717161 + 8800316100 = 149869^2 + 93810^2 .

It is an emirp because it is prime and its reverse (16233016213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31261033261 - 2¹ = 31261033259 is a prime.

Together with 31261033259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31261037261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15630516630 + 15630516631.

It is an arithmetic number, because the mean of its divisors is an integer number (15630516631).

Almost surely, 2^31261033261 is an apocalyptic number.

It is an amenable number.

31261033261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31261033261 is an equidigital number, since it uses as much as digits as its factorization.

31261033261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 28.

Adding to 31261033261 its reverse (16233016213), we get a palindrome (47494049474).

The spelling of 31261033261 in words is "thirty-one billion, two hundred sixty-one million, thirty-three thousand, two hundred sixty-one".