31430681 has 2 divisors, whose sum is σ = 31430682. Its totient is φ = 31430680.

The previous prime is 31430669. The next prime is 31430687. The reversal of 31430681 is 18603413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30349081 + 1081600 = 5509^2 + 1040^2 .

It is a cyclic number.

It is not a de Polignac number, because 31430681 - 2¹⁸ = 31168537 is a prime.

It is a super-2 number, since 2×31430681² = 1975775416247522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31430681.

It is not a weakly prime, because it can be changed into another prime (31430687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715340 + 15715341.

It is an arithmetic number, because the mean of its divisors is an integer number (15715341).

Almost surely, 2^31430681 is an apocalyptic number.

It is an amenable number.

31430681 is a deficient number, since it is larger than the sum of its proper divisors (1).

31430681 is an equidigital number, since it uses as much as digits as its factorization.

31430681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 31430681 is about 5606.3072516586. The cubic root of 31430681 is about 315.5861463920.

The spelling of 31430681 in words is "thirty-one million, four hundred thirty thousand, six hundred eighty-one".