781087 has 2 divisors, whose sum is σ = 781088. Its totient is φ = 781086.

The previous prime is 781069. The next prime is 781111. The reversal of 781087 is 780187.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 781087 - 2¹¹ = 779039 is a prime.

It is a super-2 number, since 2×781087² = 1220193803138, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 781087.

It is not a weakly prime, because it can be changed into another prime (781007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390543 + 390544.

It is an arithmetic number, because the mean of its divisors is an integer number (390544).

2⁷⁸¹⁰⁸⁷ is an apocalyptic number.

781087 is a deficient number, since it is larger than the sum of its proper divisors (1).

781087 is an equidigital number, since it uses as much as digits as its factorization.

781087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 31.

The square root of 781087 is about 883.7912649489. The cubic root of 781087 is about 92.0943817177.

Subtracting from 781087 its reverse (780187), we obtain a square (900 = 30²).

The spelling of 781087 in words is "seven hundred eighty-one thousand, eighty-seven".