31661191 has 8 divisors (see below), whose sum is σ = 33647184. Its totient is φ = 29688960.

The previous prime is 31661173. The next prime is 31661197. The reversal of 31661191 is 19116613.

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

It is a cyclic number.

It is not a de Polignac number, because 31661191 - 2¹¹ = 31659143 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 (31661197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1521 + ... + 8101.

It is an arithmetic number, because the mean of its divisors is an integer number (4205898).

Almost surely, 2^31661191 is an apocalyptic number.

31661191 is a deficient number, since it is larger than the sum of its proper divisors (1985993).

31661191 is a wasteful number, since it uses less digits than its factorization.

31661191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6881.

The product of its digits is 972, while the sum is 28.

The square root of 31661191 is about 5626.8277919268. The cubic root of 31661191 is about 316.3557621966.

The spelling of 31661191 in words is "thirty-one million, six hundred sixty-one thousand, one hundred ninety-one".