2731921 has 2 divisors, whose sum is σ = 2731922. Its totient is φ = 2731920.

The previous prime is 2731909. The next prime is 2731933. The reversal of 2731921 is 1291372.

It is a balanced prime because it is at equal distance from previous prime (2731909) and next prime (2731933).

It can be written as a sum of positive squares in only one way, i.e., 1597696 + 1134225 = 1264^2 + 1065^2 .

It is a cyclic number.

It is not a de Polignac number, because 2731921 - 2⁵ = 2731889 is a prime.

It is not a weakly prime, because it can be changed into another prime (2731901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1365960 + 1365961.

It is an arithmetic number, because the mean of its divisors is an integer number (1365961).

2^2731921 is an apocalyptic number.

It is an amenable number.

2731921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2731921 is an equidigital number, since it uses as much as digits as its factorization.

2731921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 25.

The square root of 2731921 is about 1652.8523830034. The cubic root of 2731921 is about 139.7942726656.

The spelling of 2731921 in words is "two million, seven hundred thirty-one thousand, nine hundred twenty-one".