781257427 has 2 divisors, whose sum is σ = 781257428. Its totient is φ = 781257426.

The previous prime is 781257413. The next prime is 781257431. The reversal of 781257427 is 724752187.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 781257427 - 2⁷ = 781257299 is a prime.

It is a super-2 number, since 2×781257427² = 1220726334485320658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (781257487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390628713 + 390628714.

It is an arithmetic number, because the mean of its divisors is an integer number (390628714).

Almost surely, 2^781257427 is an apocalyptic number.

781257427 is a deficient number, since it is larger than the sum of its proper divisors (1).

781257427 is an equidigital number, since it uses as much as digits as its factorization.

781257427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 219520, while the sum is 43.

The square root of 781257427 is about 27950.9825766466. The cubic root of 781257427 is about 921.0107931897.

The spelling of 781257427 in words is "seven hundred eighty-one million, two hundred fifty-seven thousand, four hundred twenty-seven".