78776993 has 4 divisors (see below), whose sum is σ = 78886080. Its totient is φ = 78667908.

The previous prime is 78776987. The next prime is 78777011. The reversal of 78776993 is 39967787.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78776993 - 2¹⁰ = 78775969 is a prime.

It is a super-2 number, since 2×78776993² = 12411629252244098, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78776923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53453 + ... + 54906.

It is an arithmetic number, because the mean of its divisors is an integer number (19721520).

Almost surely, 2^78776993 is an apocalyptic number.

It is an amenable number.

78776993 is a deficient number, since it is larger than the sum of its proper divisors (109087).

78776993 is a wasteful number, since it uses less digits than its factorization.

78776993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109086.

The product of its digits is 4000752, while the sum is 56.

The square root of 78776993 is about 8875.6404275973. The cubic root of 78776993 is about 428.6799122146.

The spelling of 78776993 in words is "seventy-eight million, seven hundred seventy-six thousand, nine hundred ninety-three".