2647681 has 2 divisors, whose sum is σ = 2647682. Its totient is φ = 2647680.

The previous prime is 2647649. The next prime is 2647693. The reversal of 2647681 is 1867462.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2640625 + 7056 = 1625^2 + 84^2 .

It is a cyclic number.

It is not a de Polignac number, because 2647681 - 2⁵ = 2647649 is a prime.

It is a super-2 number, since 2×2647681² = 14020429355522, which contains 22 as substring.

2647681 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2647081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1323840 + 1323841.

It is an arithmetic number, because the mean of its divisors is an integer number (1323841).

2^2647681 is an apocalyptic number.

It is an amenable number.

2647681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2647681 is an equidigital number, since it uses as much as digits as its factorization.

2647681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 34.

The square root of 2647681 is about 1627.1696285268. The cubic root of 2647681 is about 138.3423725969.

The spelling of 2647681 in words is "two million, six hundred forty-seven thousand, six hundred eighty-one".