78278591 has 8 divisors (see below), whose sum is σ = 86487264. Its totient is φ = 70470400.

The previous prime is 78278587. The next prime is 78278593. The reversal of 78278591 is 19587287.

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

It is a cyclic number.

It is not a de Polignac number, because 78278591 - 2² = 78278587 is a prime.

It is a super-2 number, since 2×78278591² = 12255075617890562, 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 (78278593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99710 + ... + 100491.

It is an arithmetic number, because the mean of its divisors is an integer number (10810908).

Almost surely, 2^78278591 is an apocalyptic number.

78278591 is a deficient number, since it is larger than the sum of its proper divisors (8208673).

78278591 is a wasteful number, since it uses less digits than its factorization.

78278591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200241.

The product of its digits is 282240, while the sum is 47.

The square root of 78278591 is about 8847.5189177532. The cubic root of 78278591 is about 427.7739493270.

The spelling of 78278591 in words is "seventy-eight million, two hundred seventy-eight thousand, five hundred ninety-one".