77171861990 has 8 divisors (see below), whose sum is σ = 138909351600. Its totient is φ = 30868744792.

The previous prime is 77171861969. The next prime is 77171862011. The reversal of 77171861990 is 9916817177.

It is an interprime number because it is at equal distance from previous prime (77171861969) and next prime (77171862011).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3858593090 + ... + 3858593109.

It is an arithmetic number, because the mean of its divisors is an integer number (17363668950).

Almost surely, 2^77171861990 is an apocalyptic number.

77171861990 is a deficient number, since it is larger than the sum of its proper divisors (61737489610).

77171861990 is a wasteful number, since it uses less digits than its factorization.

77171861990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7717186206.

The product of its (nonzero) digits is 1333584, while the sum is 56.

The spelling of 77171861990 in words is "seventy-seven billion, one hundred seventy-one million, eight hundred sixty-one thousand, nine hundred ninety".