31221617 has 8 divisors (see below), whose sum is σ = 37560000. Its totient is φ = 25352784.

The previous prime is 31221607. The next prime is 31221653. The reversal of 31221617 is 71612213.

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 31221617 - 2¹² = 31217521 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31221592 and 31221601.

It is not an unprimeable number, because it can be changed into a prime (31221607) 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, 117242 + ... + 117507.

It is an arithmetic number, because the mean of its divisors is an integer number (4695000).

Almost surely, 2^31221617 is an apocalyptic number.

It is an amenable number.

31221617 is a deficient number, since it is larger than the sum of its proper divisors (6338383).

31221617 is a wasteful number, since it uses less digits than its factorization.

31221617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234775.

The product of its digits is 504, while the sum is 23.

The square root of 31221617 is about 5587.6307143547. The cubic root of 31221617 is about 314.8848726840.

The spelling of 31221617 in words is "thirty-one million, two hundred twenty-one thousand, six hundred seventeen".