31516661 has 8 divisors (see below), whose sum is σ = 34716864. Its totient is φ = 28372320.

The previous prime is 31516633. The next prime is 31516669. The reversal of 31516661 is 16661513.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31516661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31516669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12776 + ... + 15041.

It is an arithmetic number, because the mean of its divisors is an integer number (4339608).

Almost surely, 2^31516661 is an apocalyptic number.

It is an amenable number.

31516661 is a deficient number, since it is larger than the sum of its proper divisors (3200203).

31516661 is a wasteful number, since it uses less digits than its factorization.

31516661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27931.

The product of its digits is 3240, while the sum is 29.

The square root of 31516661 is about 5613.9701637967. The cubic root of 31516661 is about 315.8736509509.

The spelling of 31516661 in words is "thirty-one million, five hundred sixteen thousand, six hundred sixty-one".