1217661631 has 8 divisors (see below), whose sum is σ = 1225347264. Its totient is φ = 1209999360.

The previous prime is 1217661623. The next prime is 1217661673. The reversal of 1217661631 is 1361667121.

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 1217661631 - 2³ = 1217661623 is a prime.

It is a super-2 number, since 2×1217661631² = 2965399695219160322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217661611) 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, 105271 + ... + 116263.

It is an arithmetic number, because the mean of its divisors is an integer number (153168408).

Almost surely, 2^1217661631 is an apocalyptic number.

1217661631 is a deficient number, since it is larger than the sum of its proper divisors (7685633).

1217661631 is a wasteful number, since it uses less digits than its factorization.

1217661631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11681.

The product of its digits is 9072, while the sum is 34.

The square root of 1217661631 is about 34895.0086831914. The cubic root of 1217661631 is about 1067.8466113343.

The spelling of 1217661631 in words is "one billion, two hundred seventeen million, six hundred sixty-one thousand, six hundred thirty-one".