31017661 has 2 divisors, whose sum is σ = 31017662. Its totient is φ = 31017660.

The previous prime is 31017647. The next prime is 31017683. The reversal of 31017661 is 16671013.

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., 17556100 + 13461561 = 4190^2 + 3669^2 .

It is a cyclic number.

It is not a de Polignac number, because 31017661 - 2¹⁷ = 30886589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31017601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15508830 + 15508831.

It is an arithmetic number, because the mean of its divisors is an integer number (15508831).

Almost surely, 2^31017661 is an apocalyptic number.

It is an amenable number.

31017661 is a deficient number, since it is larger than the sum of its proper divisors (1).

31017661 is an equidigital number, since it uses as much as digits as its factorization.

31017661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 31017661 is about 5569.3501416233. The cubic root of 31017661 is about 314.1977097458.

Adding to 31017661 its reverse (16671013), we get a palindrome (47688674).

It can be divided in two parts, 310 and 17661, that added together give a palindrome (17971).

The spelling of 31017661 in words is "thirty-one million, seventeen thousand, six hundred sixty-one".