77781043 has 4 divisors (see below), whose sum is σ = 78718248. Its totient is φ = 76843840.

The previous prime is 77781031. The next prime is 77781047. The reversal of 77781043 is 34018777.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34018777 = 13 ⋅2616829.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77781043 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77780993 and 77781011.

It is not an unprimeable number, because it can be changed into a prime (77781047) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468478 + ... + 468643.

It is an arithmetic number, because the mean of its divisors is an integer number (19679562).

Almost surely, 2^77781043 is an apocalyptic number.

77781043 is a deficient number, since it is larger than the sum of its proper divisors (937205).

77781043 is an equidigital number, since it uses as much as digits as its factorization.

77781043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937204.

The product of its (nonzero) digits is 32928, while the sum is 37.

The square root of 77781043 is about 8819.3561556386. The cubic root of 77781043 is about 426.8656949725.

The spelling of 77781043 in words is "seventy-seven million, seven hundred eighty-one thousand, forty-three".