990991900901 has 8 divisors (see below), whose sum is σ = 1041972237504. Its totient is φ = 940669375360.

The previous prime is 990991900849. The next prime is 990991900907. The reversal of 990991900901 is 109009199099.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990991900901 is a prime.

It is a super-2 number, since 2×990991900901² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990991900907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164449676 + ... + 164455701.

It is an arithmetic number, because the mean of its divisors is an integer number (130246529688).

Almost surely, 2^990991900901 is an apocalyptic number.

It is an amenable number.

990991900901 is a deficient number, since it is larger than the sum of its proper divisors (50980336603).

990991900901 is a wasteful number, since it uses less digits than its factorization.

990991900901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328905531.

The product of its (nonzero) digits is 531441, while the sum is 56.

The spelling of 990991900901 in words is "nine hundred ninety billion, nine hundred ninety-one million, nine hundred thousand, nine hundred one".