78378820 has 36 divisors (see below), whose sum is σ = 178238340. Its totient is φ = 28938624.

The previous prime is 78378803. The next prime is 78378847. The reversal of 78378820 is 2887387.

It can be written as a sum of positive squares in 6 ways, for example, as 14122564 + 64256256 = 3758^2 + 8016^2 .

It is a super-2 number, since 2×78378820² = 12286478849184800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8215 + ... + 14974.

It is an arithmetic number, because the mean of its divisors is an integer number (4951065).

Almost surely, 2^78378820 is an apocalyptic number.

It is an amenable number.

78378820 is an abundant number, since it is smaller than the sum of its proper divisors (99859520).

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

78378820 is a wasteful number, since it uses less digits than its factorization.

78378820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23224 (or 23209 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 43.

The square root of 78378820 is about 8853.1813490971. The cubic root of 78378820 is about 427.9564473690.

The spelling of 78378820 in words is "seventy-eight million, three hundred seventy-eight thousand, eight hundred twenty".