2730720991 has 4 divisors (see below), whose sum is σ = 2797323984. Its totient is φ = 2664118000.

The previous prime is 2730720973. The next prime is 2730721003. The reversal of 2730720991 is 1990270372.

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 2730720991 - 2⁵ = 2730720959 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2730720491) 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, 33301435 + ... + 33301516.

It is an arithmetic number, because the mean of its divisors is an integer number (699330996).

Almost surely, 2^2730720991 is an apocalyptic number.

2730720991 is a deficient number, since it is larger than the sum of its proper divisors (66602993).

2730720991 is an equidigital number, since it uses as much as digits as its factorization.

2730720991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66602992.

The product of its (nonzero) digits is 47628, while the sum is 40.

The square root of 2730720991 is about 52256.3009693568. The cubic root of 2730720991 is about 1397.7380123987.

The spelling of 2730720991 in words is "two billion, seven hundred thirty million, seven hundred twenty thousand, nine hundred ninety-one".