78400673 has 4 divisors (see below), whose sum is σ = 84431508. Its totient is φ = 72369840.

The previous prime is 78400667. The next prime is 78400697. The reversal of 78400673 is 37600487.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9560464 + 68840209 = 3092^2 + 8297^2 .

It is a cyclic number.

It is not a de Polignac number, because 78400673 - 2²² = 74206369 is a prime.

It is a super-2 number, since 2×78400673² = 12293331053705858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78400633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3015398 + ... + 3015423.

It is an arithmetic number, because the mean of its divisors is an integer number (21107877).

Almost surely, 2^78400673 is an apocalyptic number.

It is an amenable number.

78400673 is a deficient number, since it is larger than the sum of its proper divisors (6030835).

78400673 is a wasteful number, since it uses less digits than its factorization.

78400673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6030834.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 78400673 is about 8854.4154521911. The cubic root of 78400673 is about 427.9962168851.

The spelling of 78400673 in words is "seventy-eight million, four hundred thousand, six hundred seventy-three".