12021012091 has 4 divisors (see below), whose sum is σ = 13113831384. Its totient is φ = 10928192800.

The previous prime is 12021012079. The next prime is 12021012109. The reversal of 12021012091 is 19021012021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19021012021 = 11 ⋅1729182911.

It is a cyclic number.

It is not a de Polignac number, because 12021012091 - 2¹³ = 12021003899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12021012391) 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, 546409630 + ... + 546409651.

It is an arithmetic number, because the mean of its divisors is an integer number (3278457846).

Almost surely, 2^12021012091 is an apocalyptic number.

12021012091 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12021012091 is a deficient number, since it is larger than the sum of its proper divisors (1092819293).

12021012091 is a wasteful number, since it uses less digits than its factorization.

12021012091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092819292.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 12021012091 in words is "twelve billion, twenty-one million, twelve thousand, ninety-one".