77217993 has 12 divisors (see below), whose sum is σ = 115135488. Its totient is φ = 49817880.

The previous prime is 77217989. The next prime is 77218007. The reversal of 77217993 is 39971277.

It is not a de Polignac number, because 77217993 - 2² = 77217989 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (77217953) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 138105 + ... + 138662.

It is an arithmetic number, because the mean of its divisors is an integer number (9594624).

Almost surely, 2^77217993 is an apocalyptic number.

It is an amenable number.

77217993 is a deficient number, since it is larger than the sum of its proper divisors (37917495).

77217993 is a wasteful number, since it uses less digits than its factorization.

77217993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276804 (or 276801 counting only the distinct ones).

The product of its digits is 166698, while the sum is 45.

The square root of 77217993 is about 8787.3769123670. The cubic root of 77217993 is about 425.8331853644.

It can be divided in two parts, 77217 and 993, that added together give a triangular number (78210 = T₃₉₅).

The spelling of 77217993 in words is "seventy-seven million, two hundred seventeen thousand, nine hundred ninety-three".