2731909238921 has 4 divisors (see below), whose sum is σ = 2739648358932. Its totient is φ = 2724170118912.

The previous prime is 2731909238887. The next prime is 2731909238923. The reversal of 2731909238921 is 1298329091372.

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

It can be written as a sum of positive squares in 2 ways, for example, as 689582428921 + 2042326810000 = 830411^2 + 1429100^2 .

It is a cyclic number.

It is not a de Polignac number, because 2731909238921 - 2¹⁸ = 2731908976777 is a prime.

It is a super-2 number, since 2×2731909238921² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2731909238923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3869559476 + ... + 3869560181.

It is an arithmetic number, because the mean of its divisors is an integer number (684912089733).

Almost surely, 2^{2731909238921} is an apocalyptic number.

It is an amenable number.

2731909238921 is a deficient number, since it is larger than the sum of its proper divisors (7739120011).

2731909238921 is an equidigital number, since it uses as much as digits as its factorization.

2731909238921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7739120010.

The product of its (nonzero) digits is 2939328, while the sum is 56.

The spelling of 2731909238921 in words is "two trillion, seven hundred thirty-one billion, nine hundred nine million, two hundred thirty-eight thousand, nine hundred twenty-one".