78181632 has 72 divisors (see below), whose sum is σ = 231217280. Its totient is φ = 26058240.

The previous prime is 78181627. The next prime is 78181661. The reversal of 78181632 is 23618187.

78181632 is a `hidden beast` number, since 7 + 8 + 18 + 1 + 632 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×78181632² = 12224735164366848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1257 + ... + 12567.

Almost surely, 2^78181632 is an apocalyptic number.

78181632 is a gapful number since it is divisible by the number (72) 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 78181632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115608640).

78181632 is an abundant number, since it is smaller than the sum of its proper divisors (153035648).

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

78181632 is a wasteful number, since it uses less digits than its factorization.

78181632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11336 (or 11316 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 78181632 is about 8842.0377741785. The cubic root of 78181632 is about 427.5972570350.

78181632 divided by its sum of digits (36) gives a palindrome (2171712).

The spelling of 78181632 in words is "seventy-eight million, one hundred eighty-one thousand, six hundred thirty-two".