991001220022 has 16 divisors (see below), whose sum is σ = 1630597694544. Its totient is φ = 447966396000.

The previous prime is 991001220019. The next prime is 991001220109. The reversal of 991001220022 is 220022100199.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124431129 + ... + 124439092.

It is an arithmetic number, because the mean of its divisors is an integer number (101912355909).

Almost surely, 2^991001220022 is an apocalyptic number.

991001220022 is a deficient number, since it is larger than the sum of its proper divisors (639596474522).

991001220022 is a wasteful number, since it uses less digits than its factorization.

991001220022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248870415.

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

The spelling of 991001220022 in words is "nine hundred ninety-one billion, one million, two hundred twenty thousand, twenty-two".