2091901807 has 4 divisors (see below), whose sum is σ = 2092000000. Its totient is φ = 2091803616.

The previous prime is 2091901789. The next prime is 2091901813. The reversal of 2091901807 is 7081091902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2091901807 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 (2091901837) 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, 2223 + ... + 64720.

It is an arithmetic number, because the mean of its divisors is an integer number (523000000).

Almost surely, 2^2091901807 is an apocalyptic number.

2091901807 is a deficient number, since it is larger than the sum of its proper divisors (98193).

2091901807 is an equidigital number, since it uses as much as digits as its factorization.

2091901807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98192.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 2091901807 is about 45737.3130714956. The cubic root of 2091901807 is about 1278.9309528875.

The spelling of 2091901807 in words is "two billion, ninety-one million, nine hundred one thousand, eight hundred seven".