78306381 has 6 divisors (see below), whose sum is σ = 113109230. Its totient is φ = 52204248.

The previous prime is 78306373. The next prime is 78306413. The reversal of 78306381 is 18360387.

It can be written as a sum of positive squares in only one way, i.e., 71064900 + 7241481 = 8430^2 + 2691^2 .

It is not a de Polignac number, because 78306381 - 2³ = 78306373 is a prime.

It is a super-2 number, since 2×78306381² = 12263778610634322, 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 (78306181) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4350346 + ... + 4350363.

Almost surely, 2^78306381 is an apocalyptic number.

It is an amenable number.

78306381 is a deficient number, since it is larger than the sum of its proper divisors (34802849).

78306381 is a wasteful number, since it uses less digits than its factorization.

78306381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8700715 (or 8700712 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 78306381 is about 8849.0892751740. The cubic root of 78306381 is about 427.8245652591.

It can be divided in two parts, 78306 and 381, that added together give a palindrome (78687).

The spelling of 78306381 in words is "seventy-eight million, three hundred six thousand, three hundred eighty-one".