77681543 has 2 divisors, whose sum is σ = 77681544. Its totient is φ = 77681542.

The previous prime is 77681507. The next prime is 77681561. The reversal of 77681543 is 34518677.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77681543 - 2⁸ = 77681287 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77681543.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77681503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38840771 + 38840772.

It is an arithmetic number, because the mean of its divisors is an integer number (38840772).

Almost surely, 2^77681543 is an apocalyptic number.

77681543 is a deficient number, since it is larger than the sum of its proper divisors (1).

77681543 is an equidigital number, since it uses as much as digits as its factorization.

77681543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141120, while the sum is 41.

The square root of 77681543 is about 8813.7133490941. The cubic root of 77681543 is about 426.6835972150.

The spelling of 77681543 in words is "seventy-seven million, six hundred eighty-one thousand, five hundred forty-three".