31220401666 has 8 divisors (see below), whose sum is σ = 46833880320. Its totient is φ = 15609108228.

The previous prime is 31220401649. The next prime is 31220401669. The reversal of 31220401666 is 66610402213.

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

It is not an unprimeable number, because it can be changed into a prime (31220401669) 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 3 ways as a sum of consecutive naturals, for example, 510106 + ... + 568021.

It is an arithmetic number, because the mean of its divisors is an integer number (5854235040).

Almost surely, 2^31220401666 is an apocalyptic number.

31220401666 is a deficient number, since it is larger than the sum of its proper divisors (15613478654).

31220401666 is a wasteful number, since it uses less digits than its factorization.

31220401666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092608.

The product of its (nonzero) digits is 10368, while the sum is 31.

Adding to 31220401666 its reverse (66610402213), we get a palindrome (97830803879).

The spelling of 31220401666 in words is "thirty-one billion, two hundred twenty million, four hundred one thousand, six hundred sixty-six".