31012129 has 2 divisors, whose sum is σ = 31012130. Its totient is φ = 31012128.

The previous prime is 31012127. The next prime is 31012133. The reversal of 31012129 is 92121013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30250000 + 762129 = 5500^2 + 873^2 .

It is a cyclic number.

It is not a de Polignac number, because 31012129 - 2¹ = 31012127 is a prime.

It is a super-2 number, since 2×31012129² = 1923504290225282, which contains 22 as substring.

Together with 31012127, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31012127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15506064 + 15506065.

It is an arithmetic number, because the mean of its divisors is an integer number (15506065).

Almost surely, 2^31012129 is an apocalyptic number.

It is an amenable number.

31012129 is a deficient number, since it is larger than the sum of its proper divisors (1).

31012129 is an equidigital number, since it uses as much as digits as its factorization.

31012129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 31012129 is about 5568.8534726638. The cubic root of 31012129 is about 314.1790295809.

The spelling of 31012129 in words is "thirty-one million, twelve thousand, one hundred twenty-nine".