78736669 has 4 divisors (see below), whose sum is σ = 85894560. Its totient is φ = 71578780.

The previous prime is 78736663. The next prime is 78736681. The reversal of 78736669 is 96663787.

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, and also an emirpimes, since its reverse is a distinct semiprime: 96663787 = 11 ⋅8787617.

It is a cyclic number.

It is not a de Polignac number, because 78736669 - 2⁹ = 78736157 is a prime.

It is a super-2 number, since 2×78736669² = 12398926090431122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78736663) 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, 3578929 + ... + 3578950.

It is an arithmetic number, because the mean of its divisors is an integer number (21473640).

Almost surely, 2^78736669 is an apocalyptic number.

It is an amenable number.

78736669 is a deficient number, since it is larger than the sum of its proper divisors (7157891).

78736669 is a wasteful number, since it uses less digits than its factorization.

78736669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7157890.

The product of its digits is 2286144, while the sum is 52.

The square root of 78736669 is about 8873.3685261010. The cubic root of 78736669 is about 428.6067561725.

The spelling of 78736669 in words is "seventy-eight million, seven hundred thirty-six thousand, six hundred sixty-nine".