31429681 has 2 divisors, whose sum is σ = 31429682. Its totient is φ = 31429680.

The previous prime is 31429679. The next prime is 31429703. The reversal of 31429681 is 18692413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27206656 + 4223025 = 5216^2 + 2055^2 .

It is a cyclic number.

It is not a de Polignac number, because 31429681 - 2¹ = 31429679 is a prime.

It is a super-2 number, since 2×31429681² = 1975649695523522, which contains 22 as substring.

Together with 31429679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31429621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15714840 + 15714841.

It is an arithmetic number, because the mean of its divisors is an integer number (15714841).

Almost surely, 2^31429681 is an apocalyptic number.

It is an amenable number.

31429681 is a deficient number, since it is larger than the sum of its proper divisors (1).

31429681 is an equidigital number, since it uses as much as digits as its factorization.

31429681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 31429681 is about 5606.2180656839. The cubic root of 31429681 is about 315.5827994554.

The spelling of 31429681 in words is "thirty-one million, four hundred twenty-nine thousand, six hundred eighty-one".