11918292821 has 4 divisors (see below), whose sum is σ = 11928963852. Its totient is φ = 11907621792.

The previous prime is 11918292803. The next prime is 11918292823. The reversal of 11918292821 is 12829281911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12829281911 = 8893 ⋅1442627.

It can be written as a sum of positive squares in 2 ways, for example, as 5953819921 + 5964472900 = 77161^2 + 77230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11918292821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11918292823) 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, 5333840 + ... + 5336073.

It is an arithmetic number, because the mean of its divisors is an integer number (2982240963).

Almost surely, 2^11918292821 is an apocalyptic number.

It is an amenable number.

11918292821 is a deficient number, since it is larger than the sum of its proper divisors (10671031).

11918292821 is a wasteful number, since it uses less digits than its factorization.

11918292821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10671030.

The product of its digits is 41472, while the sum is 44.

The spelling of 11918292821 in words is "eleven billion, nine hundred eighteen million, two hundred ninety-two thousand, eight hundred twenty-one".