2720981 has 2 divisors, whose sum is σ = 2720982. Its totient is φ = 2720980.

The previous prime is 2720953. The next prime is 2720987. The reversal of 2720981 is 1890272.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2592100 + 128881 = 1610^2 + 359^2 .

It is a cyclic number.

It is not a de Polignac number, because 2720981 - 2⁶ = 2720917 is a prime.

It is a super-2 number, since 2×2720981² = 14807475204722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2720987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1360490 + 1360491.

It is an arithmetic number, because the mean of its divisors is an integer number (1360491).

2^2720981 is an apocalyptic number.

It is an amenable number.

2720981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2720981 is an equidigital number, since it uses as much as digits as its factorization.

2720981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 2720981 is about 1649.5396327461. The cubic root of 2720981 is about 139.6074205900.

The spelling of 2720981 in words is "two million, seven hundred twenty thousand, nine hundred eighty-one".