31217429 has 2 divisors, whose sum is σ = 31217430. Its totient is φ = 31217428.

The previous prime is 31217419. The next prime is 31217443. The reversal of 31217429 is 92471213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27615025 + 3602404 = 5255^2 + 1898^2 .

It is a cyclic number.

It is not a de Polignac number, because 31217429 - 2¹⁶ = 31151893 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31217419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15608714 + 15608715.

It is an arithmetic number, because the mean of its divisors is an integer number (15608715).

Almost surely, 2^31217429 is an apocalyptic number.

It is an amenable number.

31217429 is a deficient number, since it is larger than the sum of its proper divisors (1).

31217429 is an equidigital number, since it uses as much as digits as its factorization.

31217429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 29.

The square root of 31217429 is about 5587.2559454530. The cubic root of 31217429 is about 314.8707927298.

The spelling of 31217429 in words is "thirty-one million, two hundred seventeen thousand, four hundred twenty-nine".