781423031 has 2 divisors, whose sum is σ = 781423032. Its totient is φ = 781423030.

The previous prime is 781423021. The next prime is 781423079. The reversal of 781423031 is 130324187.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-781423031 is a prime.

It is a super-2 number, since 2×781423031² = 1221243906754453922, which contains 22 as substring.

It is a Sophie Germain prime.

It is equal to p_40239146 and since 781423031 and 40239146 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 = 781422985 and 781423003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (781423021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390711515 + 390711516.

It is an arithmetic number, because the mean of its divisors is an integer number (390711516).

Almost surely, 2^781423031 is an apocalyptic number.

781423031 is a deficient number, since it is larger than the sum of its proper divisors (1).

781423031 is an equidigital number, since it uses as much as digits as its factorization.

781423031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 781423031 is about 27953.9448200071. The cubic root of 781423031 is about 921.0758644840.

The spelling of 781423031 in words is "seven hundred eighty-one million, four hundred twenty-three thousand, thirty-one".