11902198021 has 4 divisors (see below), whose sum is σ = 13602512032. Its totient is φ = 10201884012.

The previous prime is 11902198003. The next prime is 11902198039. The reversal of 11902198021 is 12089120911.

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: 12089120911 = 7 ⋅1727017273.

It is an interprime number because it is at equal distance from previous prime (11902198003) and next prime (11902198039).

It is a cyclic number.

It is not a de Polignac number, because 11902198021 - 2²³ = 11893809413 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 (11902198421) 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, 850156995 + ... + 850157008.

It is an arithmetic number, because the mean of its divisors is an integer number (3400628008).

Almost surely, 2^11902198021 is an apocalyptic number.

It is an amenable number.

11902198021 is a deficient number, since it is larger than the sum of its proper divisors (1700314011).

11902198021 is an equidigital number, since it uses as much as digits as its factorization.

11902198021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1700314010.

The product of its (nonzero) digits is 2592, while the sum is 34.

The spelling of 11902198021 in words is "eleven billion, nine hundred two million, one hundred ninety-eight thousand, twenty-one".