2661731 has 2 divisors, whose sum is σ = 2661732. Its totient is φ = 2661730.

The previous prime is 2661689. The next prime is 2661733. The reversal of 2661731 is 1371662.

2661731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661731 is a prime.

It is a super-2 number, since 2×2661731² = 14169623832722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 2661733, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2661731.

It is not a weakly prime, because it can be changed into another prime (2661733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330865 + 1330866.

It is an arithmetic number, because the mean of its divisors is an integer number (1330866).

2^2661731 is an apocalyptic number.

2661731 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661731 is an equidigital number, since it uses as much as digits as its factorization.

2661731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 26.

The square root of 2661731 is about 1631.4812288224. The cubic root of 2661731 is about 138.5866470287.

The spelling of 2661731 in words is "two million, six hundred sixty-one thousand, seven hundred thirty-one".