78217650 has 240 divisors, whose sum is σ = 259269120. Its totient is φ = 17107200.

The previous prime is 78217631. The next prime is 78217673. The reversal of 78217650 is 5671287.

It is a super-2 number, since 2×78217650² = 12236001543045000, which contains 22 as substring.

It is an unprimeable number.

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 119 ways as a sum of consecutive naturals, for example, 878806 + ... + 878894.

It is an arithmetic number, because the mean of its divisors is an integer number (1080288).

Almost surely, 2^78217650 is an apocalyptic number.

78217650 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 78217650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129634560).

78217650 is an abundant number, since it is smaller than the sum of its proper divisors (181051470).

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

78217650 is a wasteful number, since it uses less digits than its factorization.

78217650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 78217650 is about 8844.0742873406. The cubic root of 78217650 is about 427.6629111327.

The spelling of 78217650 in words is "seventy-eight million, two hundred seventeen thousand, six hundred fifty".