78209880 has 192 divisors, whose sum is σ = 279728640. Its totient is φ = 17434368.

The previous prime is 78209863. The next prime is 78209903. The reversal of 78209880 is 8890287.

It is a happy number.

It is a super-2 number, since 2×78209880² = 12233570659228800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 276219 + ... + 276501.

It is an arithmetic number, because the mean of its divisors is an integer number (1456920).

Almost surely, 2^78209880 is an apocalyptic number.

78209880 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 78209880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139864320).

78209880 is an abundant number, since it is smaller than the sum of its proper divisors (201518760).

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

78209880 is a wasteful number, since it uses less digits than its factorization.

78209880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358 (or 347 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 78209880 is about 8843.6349992523. The cubic root of 78209880 is about 427.6487495768.

The spelling of 78209880 in words is "seventy-eight million, two hundred nine thousand, eight hundred eighty".