2140781 has 2 divisors, whose sum is σ = 2140782. Its totient is φ = 2140780.

The previous prime is 2140769. The next prime is 2140807. The reversal of 2140781 is 1870412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2128681 + 12100 = 1459^2 + 110^2 .

It is a cyclic number.

It is not a de Polignac number, because 2140781 - 2¹⁰ = 2139757 is a prime.

It is a super-2 number, since 2×2140781² = 9165886579922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2140741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1070390 + 1070391.

It is an arithmetic number, because the mean of its divisors is an integer number (1070391).

2^2140781 is an apocalyptic number.

It is an amenable number.

2140781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2140781 is an equidigital number, since it uses as much as digits as its factorization.

2140781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 2140781 is about 1463.1407997865. The cubic root of 2140781 is about 128.8815490216.

The spelling of 2140781 in words is "two million, one hundred forty thousand, seven hundred eighty-one".