1217048891 has 4 divisors (see below), whose sum is σ = 1217127912. Its totient is φ = 1216969872.

The previous prime is 1217048869. The next prime is 1217048893. The reversal of 1217048891 is 1988407121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1217048891 - 2⁶ = 1217048827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1217048893) 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, 8066 + ... + 49991.

It is an arithmetic number, because the mean of its divisors is an integer number (304281978).

Almost surely, 2^1217048891 is an apocalyptic number.

1217048891 is a deficient number, since it is larger than the sum of its proper divisors (79021).

1217048891 is an equidigital number, since it uses as much as digits as its factorization.

1217048891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79020.

The product of its (nonzero) digits is 32256, while the sum is 41.

The square root of 1217048891 is about 34886.2278127057. The cubic root of 1217048891 is about 1067.6674641068.

The spelling of 1217048891 in words is "one billion, two hundred seventeen million, forty-eight thousand, eight hundred ninety-one".