1216881793 has 4 divisors (see below), whose sum is σ = 1232285440. Its totient is φ = 1201478148.

The previous prime is 1216881773. The next prime is 1216881821. The reversal of 1216881793 is 3971886121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3971886121 = 7 ⋅567412303.

It is a cyclic number.

It is not a de Polignac number, because 1216881793 - 2⁵ = 1216881761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216881773) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7701705 + ... + 7701862.

It is an arithmetic number, because the mean of its divisors is an integer number (308071360).

Almost surely, 2^1216881793 is an apocalyptic number.

It is an amenable number.

1216881793 is a deficient number, since it is larger than the sum of its proper divisors (15403647).

1216881793 is an equidigital number, since it uses as much as digits as its factorization.

1216881793 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15403646.

The product of its digits is 145152, while the sum is 46.

The square root of 1216881793 is about 34883.8328312701. The cubic root of 1216881793 is about 1067.6185991119.

It can be divided in two parts, 12168 and 81793, that added together give a triangular number (93961 = T₄₃₃).

The spelling of 1216881793 in words is "one billion, two hundred sixteen million, eight hundred eighty-one thousand, seven hundred ninety-three".