991000122022 has 4 divisors (see below), whose sum is σ = 1486500183036. Its totient is φ = 495500061010.

The previous prime is 991000121927. The next prime is 991000122023. The reversal of 991000122022 is 220221000199.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991000122023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 247750030504 + ... + 247750030507.

It is an arithmetic number, because the mean of its divisors is an integer number (371625045759).

Almost surely, 2^991000122022 is an apocalyptic number.

991000122022 is a deficient number, since it is larger than the sum of its proper divisors (495500061014).

991000122022 is a wasteful number, since it uses less digits than its factorization.

991000122022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495500061013.

The product of its (nonzero) digits is 1296, while the sum is 28.

The spelling of 991000122022 in words is "nine hundred ninety-one billion, one hundred twenty-two thousand, twenty-two".