77142191 has 4 divisors (see below), whose sum is σ = 88162512. Its totient is φ = 66121872.

The previous prime is 77142187. The next prime is 77142199. The reversal of 77142191 is 19124177.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19124177 = 193 ⋅99089.

It is a cyclic number.

It is not a de Polignac number, because 77142191 - 2² = 77142187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77142199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5510150 + ... + 5510163.

It is an arithmetic number, because the mean of its divisors is an integer number (22040628).

Almost surely, 2^77142191 is an apocalyptic number.

77142191 is a deficient number, since it is larger than the sum of its proper divisors (11020321).

77142191 is a wasteful number, since it uses less digits than its factorization.

77142191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11020320.

The product of its digits is 3528, while the sum is 32.

The square root of 77142191 is about 8783.0627346046. The cubic root of 77142191 is about 425.6937982691.

The spelling of 77142191 in words is "seventy-seven million, one hundred forty-two thousand, one hundred ninety-one".