31671661 has 4 divisors (see below), whose sum is σ = 36196192. Its totient is φ = 27147132.

The previous prime is 31671649. The next prime is 31671671. The reversal of 31671661 is 16617613.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31671661 - 2¹¹ = 31669613 is a prime.

It is a super-3 number, since 3×31671661³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31671671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2262255 + ... + 2262268.

It is an arithmetic number, because the mean of its divisors is an integer number (9049048).

Almost surely, 2^31671661 is an apocalyptic number.

It is an amenable number.

31671661 is a deficient number, since it is larger than the sum of its proper divisors (4524531).

31671661 is an equidigital number, since it uses as much as digits as its factorization.

31671661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4524530.

The product of its digits is 4536, while the sum is 31.

The square root of 31671661 is about 5627.7580793776. The cubic root of 31671661 is about 316.3906301183.

The spelling of 31671661 in words is "thirty-one million, six hundred seventy-one thousand, six hundred sixty-one".