31151641 has 2 divisors, whose sum is σ = 31151642. Its totient is φ = 31151640.

The previous prime is 31151639. The next prime is 31151671. The reversal of 31151641 is 14615113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31036041 + 115600 = 5571^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 31151641 - 2¹ = 31151639 is a prime.

Together with 31151639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31151671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15575820 + 15575821.

It is an arithmetic number, because the mean of its divisors is an integer number (15575821).

Almost surely, 2^31151641 is an apocalyptic number.

It is an amenable number.

31151641 is a deficient number, since it is larger than the sum of its proper divisors (1).

31151641 is an equidigital number, since it uses as much as digits as its factorization.

31151641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 22.

The square root of 31151641 is about 5581.3655139222. The cubic root of 31151641 is about 314.6494496220.

Adding to 31151641 its reverse (14615113), we get a palindrome (45766754).

The spelling of 31151641 in words is "thirty-one million, one hundred fifty-one thousand, six hundred forty-one".