31430561 has 2 divisors, whose sum is σ = 31430562. Its totient is φ = 31430560.

The previous prime is 31430551. The next prime is 31430587. The reversal of 31430561 is 16503413.

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., 30913600 + 516961 = 5560^2 + 719^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31430561 is a prime.

It is a super-3 number, since 3×31430561³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31430551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715280 + 15715281.

It is an arithmetic number, because the mean of its divisors is an integer number (15715281).

Almost surely, 2^31430561 is an apocalyptic number.

It is an amenable number.

31430561 is a deficient number, since it is larger than the sum of its proper divisors (1).

31430561 is an equidigital number, since it uses as much as digits as its factorization.

31430561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 31430561 is about 5606.2965494166. The cubic root of 31430561 is about 315.5857447634.

Adding to 31430561 its reverse (16503413), we get a palindrome (47933974).

The spelling of 31430561 in words is "thirty-one million, four hundred thirty thousand, five hundred sixty-one".