78420730 has 8 divisors (see below), whose sum is σ = 141157332. Its totient is φ = 31368288.

The previous prime is 78420721. The next prime is 78420737. The reversal of 78420730 is 3702487.

It can be written as a sum of positive squares in 2 ways, for example, as 78269409 + 151321 = 8847^2 + 389^2 .

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

It is a super-2 number, since 2×78420730² = 12299621787465800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78420692 and 78420701.

It is not an unprimeable number, because it can be changed into a prime (78420737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3921027 + ... + 3921046.

Almost surely, 2^78420730 is an apocalyptic number.

78420730 is a deficient number, since it is larger than the sum of its proper divisors (62736602).

78420730 is a wasteful number, since it uses less digits than its factorization.

78420730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7842080.

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 78420730 is about 8855.5479785274. The cubic root of 78420730 is about 428.0327114196.

The spelling of 78420730 in words is "seventy-eight million, four hundred twenty thousand, seven hundred thirty".