31729129 has 2 divisors, whose sum is σ = 31729130. Its totient is φ = 31729128.

The previous prime is 31729127. The next prime is 31729133. The reversal of 31729129 is 92192713.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31304025 + 425104 = 5595^2 + 652^2 .

It is an emirp because it is prime and its reverse (92192713) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31729129 - 2¹ = 31729127 is a prime.

Together with 31729127, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 31729094 and 31729103.

It is not a weakly prime, because it can be changed into another prime (31729127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15864564 + 15864565.

It is an arithmetic number, because the mean of its divisors is an integer number (15864565).

Almost surely, 2^31729129 is an apocalyptic number.

It is an amenable number.

31729129 is a deficient number, since it is larger than the sum of its proper divisors (1).

31729129 is an equidigital number, since it uses as much as digits as its factorization.

31729129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 34.

The square root of 31729129 is about 5632.8615285661. The cubic root of 31729129 is about 316.5818773300.

The spelling of 31729129 in words is "thirty-one million, seven hundred twenty-nine thousand, one hundred twenty-nine".