78382661 has 4 divisors (see below), whose sum is σ = 89580192. Its totient is φ = 67185132.

The previous prime is 78382639. The next prime is 78382669. The reversal of 78382661 is 16628387.

It is a happy number.

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 not a de Polignac number, because 78382661 - 2¹⁸ = 78120517 is a prime.

It is a super-2 number, since 2×78382661² = 12287683090881842, 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 (78382669) 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, 5598755 + ... + 5598768.

It is an arithmetic number, because the mean of its divisors is an integer number (22395048).

Almost surely, 2^78382661 is an apocalyptic number.

It is an amenable number.

78382661 is a deficient number, since it is larger than the sum of its proper divisors (11197531).

78382661 is a wasteful number, since it uses less digits than its factorization.

78382661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11197530.

The product of its digits is 96768, while the sum is 41.

The square root of 78382661 is about 8853.3982741092. The cubic root of 78382661 is about 427.9634380070.

The spelling of 78382661 in words is "seventy-eight million, three hundred eighty-two thousand, six hundred sixty-one".