31661351 has 2 divisors, whose sum is σ = 31661352. Its totient is φ = 31661350.

The previous prime is 31661309. The next prime is 31661369. The reversal of 31661351 is 15316613.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31661351 - 2¹⁴ = 31644967 is a prime.

It is a super-2 number, since 2×31661351² = 2004882294290402, 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 31661351.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31664351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15830675 + 15830676.

It is an arithmetic number, because the mean of its divisors is an integer number (15830676).

Almost surely, 2^31661351 is an apocalyptic number.

31661351 is a deficient number, since it is larger than the sum of its proper divisors (1).

31661351 is an equidigital number, since it uses as much as digits as its factorization.

31661351 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 26.

The square root of 31661351 is about 5626.8420095112. The cubic root of 31661351 is about 316.3562950975.

Adding to 31661351 its reverse (15316613), we get a palindrome (46977964).

The spelling of 31661351 in words is "thirty-one million, six hundred sixty-one thousand, three hundred fifty-one".