31506149 has 2 divisors, whose sum is σ = 31506150. Its totient is φ = 31506148.

The previous prime is 31506119. The next prime is 31506173. The reversal of 31506149 is 94160513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29702500 + 1803649 = 5450^2 + 1343^2 .

It is an emirp because it is prime and its reverse (94160513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31506149 - 2²⁰ = 30457573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31506119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15753074 + 15753075.

It is an arithmetic number, because the mean of its divisors is an integer number (15753075).

Almost surely, 2^31506149 is an apocalyptic number.

It is an amenable number.

31506149 is a deficient number, since it is larger than the sum of its proper divisors (1).

31506149 is an equidigital number, since it uses as much as digits as its factorization.

31506149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 31506149 is about 5613.0338498890. The cubic root of 31506149 is about 315.8385284374.

The spelling of 31506149 in words is "thirty-one million, five hundred six thousand, one hundred forty-nine".