781742041 has 2 divisors, whose sum is σ = 781742042. Its totient is φ = 781742040.

The previous prime is 781742033. The next prime is 781742083. The reversal of 781742041 is 140247187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 727866441 + 53875600 = 26979^2 + 7340^2 .

It is an emirp because it is prime and its reverse (140247187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 781742041 - 2³ = 781742033 is a prime.

It is a super-2 number, since 2×781742041² = 1222241237333691362, which contains 22 as substring.

It is equal to p_40254577 and since 781742041 and 40254577 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 781741988 and 781742006.

It is not a weakly prime, because it can be changed into another prime (781742011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390871020 + 390871021.

It is an arithmetic number, because the mean of its divisors is an integer number (390871021).

Almost surely, 2^781742041 is an apocalyptic number.

It is an amenable number.

781742041 is a deficient number, since it is larger than the sum of its proper divisors (1).

781742041 is an equidigital number, since it uses as much as digits as its factorization.

781742041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12544, while the sum is 34.

The square root of 781742041 is about 27959.6502302872. The cubic root of 781742041 is about 921.2011881666.

The spelling of 781742041 in words is "seven hundred eighty-one million, seven hundred forty-two thousand, forty-one".