78311387 has 8 divisors (see below), whose sum is σ = 97635072. Its totient is φ = 61021800.

The previous prime is 78311383. The next prime is 78311393.

78311387 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 78311387 - 2² = 78311383 is a prime.

It is a super-2 number, since 2×78311387² = 12265346667727538, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78311387.

It is not an unprimeable number, because it can be changed into a prime (78311381) 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, 508439 + ... + 508592.

It is an arithmetic number, because the mean of its divisors is an integer number (12204384).

Almost surely, 2^78311387 is an apocalyptic number.

78311387 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

78311387 is a deficient number, since it is larger than the sum of its proper divisors (19323685).

78311387 is a wasteful number, since it uses less digits than its factorization.

78311387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017049.

The product of its digits is 28224, while the sum is 38.

The square root of 78311387 is about 8849.3721246199. The cubic root of 78311387 is about 427.8336817752.

The spelling of 78311387 in words is "seventy-eight million, three hundred eleven thousand, three hundred eighty-seven".