78344387 has 16 divisors (see below), whose sum is σ = 87070464. Its totient is φ = 69900000.

The previous prime is 78344351. The next prime is 78344401.

78344387 is nontrivially palindromic in base 10.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78344387 is a prime.

It is a super-2 number, since 2×78344387² = 12275685948811538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78344587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167528 + ... + 167994.

It is an arithmetic number, because the mean of its divisors is an integer number (5441904).

Almost surely, 2^78344387 is an apocalyptic number.

78344387 is a deficient number, since it is larger than the sum of its proper divisors (8726077).

78344387 is a wasteful number, since it uses less digits than its factorization.

78344387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730.

The product of its digits is 451584, while the sum is 44.

The square root of 78344387 is about 8851.2364672965. The cubic root of 78344387 is about 427.8937689449.

It can be divided in two parts, 7834 and 4387, that added together give a palindrome (12221).

The spelling of 78344387 in words is "seventy-eight million, three hundred forty-four thousand, three hundred eighty-seven".