78170820 has 192 divisors, whose sum is σ = 273960960. Its totient is φ = 16215552.

The previous prime is 78170803. The next prime is 78170821. The reversal of 78170820 is 2807187.

It is a super-2 number, since 2×78170820² = 12221354198944800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78170821) 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 63 ways as a sum of consecutive naturals, for example, 562311 + ... + 562449.

It is an arithmetic number, because the mean of its divisors is an integer number (1426880).

Almost surely, 2^78170820 is an apocalyptic number.

78170820 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78170820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136980480).

78170820 is an abundant number, since it is smaller than the sum of its proper divisors (195790140).

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

78170820 is a wasteful number, since it uses less digits than its factorization.

78170820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 272 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 33.

The square root of 78170820 is about 8841.4263555153. The cubic root of 78170820 is about 427.5775448402.

The spelling of 78170820 in words is "seventy-eight million, one hundred seventy thousand, eight hundred twenty".