1217397816 has 64 divisors (see below), whose sum is σ = 3411655200. Its totient is φ = 402200064.

The previous prime is 1217397781. The next prime is 1217397827. The reversal of 1217397816 is 6187937121.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 531 + ... + 49346.

Almost surely, 2^1217397816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1217397816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1705827600).

1217397816 is an abundant number, since it is smaller than the sum of its proper divisors (2194257384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1217397816 is a wasteful number, since it uses less digits than its factorization.

1217397816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50005 (or 49995 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 1217397816 is about 34891.2283532695. The cubic root of 1217397816 is about 1067.7694869252.

It can be divided in two parts, 121 and 7397816, that added together give a palindrome (7397937).

The spelling of 1217397816 in words is "one billion, two hundred seventeen million, three hundred ninety-seven thousand, eight hundred sixteen".