78386431 has 4 divisors (see below), whose sum is σ = 78411592. Its totient is φ = 78361272.

The previous prime is 78386389. The next prime is 78386443. The reversal of 78386431 is 13468387.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13468387 = 401 ⋅33587.

It is a cyclic number.

It is not a de Polignac number, because 78386431 - 2¹³ = 78378239 is a prime.

It is a super-2 number, since 2×78386431² = 12288865129835522, 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 (78386491) 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, 7116 + ... + 14401.

It is an arithmetic number, because the mean of its divisors is an integer number (19602898).

Almost surely, 2^78386431 is an apocalyptic number.

78386431 is a deficient number, since it is larger than the sum of its proper divisors (25161).

78386431 is a wasteful number, since it uses less digits than its factorization.

78386431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25160.

The product of its digits is 96768, while the sum is 40.

The square root of 78386431 is about 8853.6111841440. The cubic root of 78386431 is about 427.9702992026.

The spelling of 78386431 in words is "seventy-eight million, three hundred eighty-six thousand, four hundred thirty-one".