781940077 has 4 divisors (see below), whose sum is σ = 783982080. Its totient is φ = 779898076.

The previous prime is 781940059. The next prime is 781940087. The reversal of 781940077 is 770049187.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 781940077 - 2²⁷ = 647722349 is a prime.

It is a super-2 number, since 2×781940077² = 1222860568037531858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781940017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1020427 + ... + 1021192.

It is an arithmetic number, because the mean of its divisors is an integer number (195995520).

Almost surely, 2^781940077 is an apocalyptic number.

It is an amenable number.

781940077 is a deficient number, since it is larger than the sum of its proper divisors (2042003).

781940077 is a wasteful number, since it uses less digits than its factorization.

781940077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2042002.

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 781940077 is about 27963.1914666406. The cubic root of 781940077 is about 921.2789698329.

The spelling of 781940077 in words is "seven hundred eighty-one million, nine hundred forty thousand, seventy-seven".