1540681 has 2 divisors, whose sum is σ = 1540682. Its totient is φ = 1540680.

The previous prime is 1540673. The next prime is 1540687. The reversal of 1540681 is 1860451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1299600 + 241081 = 1140^2 + 491^2 .

It is a cyclic number.

It is not a de Polignac number, because 1540681 - 2³ = 1540673 is a prime.

It is a super-3 number, since 3×1540681³ = 10971333965074923723, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1540687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770340 + 770341.

It is an arithmetic number, because the mean of its divisors is an integer number (770341).

2^1540681 is an apocalyptic number.

It is an amenable number.

1540681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540681 is an equidigital number, since it uses as much as digits as its factorization.

1540681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1540681 is about 1241.2417169915. The cubic root of 1540681 is about 115.4970545778.

The spelling of 1540681 in words is "one million, five hundred forty thousand, six hundred eighty-one".