31668481 has 4 divisors (see below), whose sum is σ = 34104532. Its totient is φ = 29232432.

The previous prime is 31668479. The next prime is 31668487. The reversal of 31668481 is 18486613.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18486613 = 41 ⋅450893.

It can be written as a sum of positive squares in 2 ways, for example, as 1418481 + 30250000 = 1191^2 + 5500^2 .

It is a cyclic number.

It is not a de Polignac number, because 31668481 - 2¹ = 31668479 is a prime.

It is a super-2 number, since 2×31668481² = 2005785377694722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31668481.

It is not an unprimeable number, because it can be changed into a prime (31668487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1218006 + ... + 1218031.

It is an arithmetic number, because the mean of its divisors is an integer number (8526133).

Almost surely, 2^31668481 is an apocalyptic number.

It is an amenable number.

31668481 is a deficient number, since it is larger than the sum of its proper divisors (2436051).

31668481 is a wasteful number, since it uses less digits than its factorization.

31668481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2436050.

The product of its digits is 27648, while the sum is 37.

The square root of 31668481 is about 5627.4755441494. The cubic root of 31668481 is about 316.3800406739.

The spelling of 31668481 in words is "thirty-one million, six hundred sixty-eight thousand, four hundred eighty-one".