77942191 has 2 divisors, whose sum is σ = 77942192. Its totient is φ = 77942190.

The previous prime is 77942159. The next prime is 77942197. The reversal of 77942191 is 19124977.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77942191 - 2⁵ = 77942159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77942197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38971095 + 38971096.

It is an arithmetic number, because the mean of its divisors is an integer number (38971096).

Almost surely, 2^77942191 is an apocalyptic number.

77942191 is a deficient number, since it is larger than the sum of its proper divisors (1).

77942191 is an equidigital number, since it uses as much as digits as its factorization.

77942191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 40.

The square root of 77942191 is about 8828.4874695499. The cubic root of 77942191 is about 427.1602873275.

The spelling of 77942191 in words is "seventy-seven million, nine hundred forty-two thousand, one hundred ninety-one".