78346440 has 80 divisors (see below), whose sum is σ = 263341980. Its totient is φ = 20891520.

The previous prime is 78346399. The next prime is 78346507. The reversal of 78346440 is 4464387.

78346440 is a `hidden beast` number, since 7 + 8 + 3 + 4 + 644 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 78110244 + 236196 = 8838^2 + 486^2 .

It is a super-2 number, since 2×78346440² = 12276329321347200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78346395 and 78346404.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 8851 + ... + 15330.

Almost surely, 2^78346440 is an apocalyptic number.

It is an amenable number.

78346440 is an abundant number, since it is smaller than the sum of its proper divisors (184995540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78346440 is a wasteful number, since it uses less digits than its factorization.

78346440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24204 (or 24191 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 78346440 is about 8851.3524390344. The cubic root of 78346440 is about 427.8975065376.

The spelling of 78346440 in words is "seventy-eight million, three hundred forty-six thousand, four hundred forty".