31391147 has 2 divisors, whose sum is σ = 31391148. Its totient is φ = 31391146.

The previous prime is 31391131. The next prime is 31391153. The reversal of 31391147 is 74119313.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31391147 - 2⁴ = 31391131 is a prime.

It is not a weakly prime, because it can be changed into another prime (31391167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15695573 + 15695574.

It is an arithmetic number, because the mean of its divisors is an integer number (15695574).

Almost surely, 2^31391147 is an apocalyptic number.

31391147 is a deficient number, since it is larger than the sum of its proper divisors (1).

31391147 is an equidigital number, since it uses as much as digits as its factorization.

31391147 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2268, while the sum is 29.

The square root of 31391147 is about 5602.7802919622. The cubic root of 31391147 is about 315.4537744869.

The spelling of 31391147 in words is "thirty-one million, three hundred ninety-one thousand, one hundred forty-seven".