77691143 has 2 divisors, whose sum is σ = 77691144. Its totient is φ = 77691142.

The previous prime is 77691137. The next prime is 77691181. The reversal of 77691143 is 34119677.

It is an a-pointer prime, because the next prime (77691181) can be obtained adding 77691143 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77691143 - 2⁸ = 77690887 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77691097 and 77691106.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77690143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38845571 + 38845572.

It is an arithmetic number, because the mean of its divisors is an integer number (38845572).

Almost surely, 2^77691143 is an apocalyptic number.

77691143 is a deficient number, since it is larger than the sum of its proper divisors (1).

77691143 is an equidigital number, since it uses as much as digits as its factorization.

77691143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 38.

The square root of 77691143 is about 8814.2579381364. The cubic root of 77691143 is about 426.7011732210.

It can be divided in two parts, 776 and 91143, that added together give a palindrome (91919).

The spelling of 77691143 in words is "seventy-seven million, six hundred ninety-one thousand, one hundred forty-three".