2851720091 has 4 divisors (see below), whose sum is σ = 3110967384. Its totient is φ = 2592472800.

The previous prime is 2851720087. The next prime is 2851720147. The reversal of 2851720091 is 1900271582.

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

It is a cyclic number.

It is not a de Polignac number, because 2851720091 - 2² = 2851720087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2851720061) 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, 129623630 + ... + 129623651.

It is an arithmetic number, because the mean of its divisors is an integer number (777741846).

Almost surely, 2^2851720091 is an apocalyptic number.

2851720091 is a deficient number, since it is larger than the sum of its proper divisors (259247293).

2851720091 is a wasteful number, since it uses less digits than its factorization.

2851720091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259247292.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 2851720091 is about 53401.4989583626. The cubic root of 2851720091 is about 1418.0851149770.

The spelling of 2851720091 in words is "two billion, eight hundred fifty-one million, seven hundred twenty thousand, ninety-one".