31561967 has 2 divisors, whose sum is σ = 31561968. Its totient is φ = 31561966.

The previous prime is 31561939. The next prime is 31561969. The reversal of 31561967 is 76916513.

It is a strong prime.

It is an emirp because it is prime and its reverse (76916513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31561967 - 2⁶ = 31561903 is a prime.

Together with 31561969, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31561967.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31561969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15780983 + 15780984.

It is an arithmetic number, because the mean of its divisors is an integer number (15780984).

Almost surely, 2^31561967 is an apocalyptic number.

31561967 is a deficient number, since it is larger than the sum of its proper divisors (1).

31561967 is an equidigital number, since it uses as much as digits as its factorization.

31561967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 38.

The square root of 31561967 is about 5618.0038269834. The cubic root of 31561967 is about 316.0249372779.

The spelling of 31561967 in words is "thirty-one million, five hundred sixty-one thousand, nine hundred sixty-seven".