1099196821 has 4 divisors (see below), whose sum is σ = 1099313644. Its totient is φ = 1099080000.

The previous prime is 1099196809. The next prime is 1099196827. The reversal of 1099196821 is 1286919901.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1286919901 = 2203 ⋅584167.

It can be written as a sum of positive squares in 2 ways, for example, as 925984900 + 173211921 = 30430^2 + 13161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1099196821 - 2²¹ = 1097099669 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 (1099196827) 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, 42930 + ... + 63571.

It is an arithmetic number, because the mean of its divisors is an integer number (274828411).

Almost surely, 2^1099196821 is an apocalyptic number.

It is an amenable number.

1099196821 is a deficient number, since it is larger than the sum of its proper divisors (116823).

1099196821 is a wasteful number, since it uses less digits than its factorization.

1099196821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116822.

The product of its (nonzero) digits is 69984, while the sum is 46.

The square root of 1099196821 is about 33154.1373134636. The cubic root of 1099196821 is about 1032.0288101270.

The spelling of 1099196821 in words is "one billion, ninety-nine million, one hundred ninety-six thousand, eight hundred twenty-one".