78405912 has 96 divisors (see below), whose sum is σ = 230346480. Its totient is φ = 23950080.

The previous prime is 78405911. The next prime is 78405947. The reversal of 78405912 is 21950487.

It is a super-2 number, since 2×78405912² = 12294974073103488, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78405911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 197298 + ... + 197694.

Almost surely, 2^78405912 is an apocalyptic number.

78405912 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 78405912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115173240).

78405912 is an abundant number, since it is smaller than the sum of its proper divisors (151940568).

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

78405912 is a wasteful number, since it uses less digits than its factorization.

78405912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 78405912 is about 8854.7112883481. The cubic root of 78405912 is about 428.0057500610.

The spelling of 78405912 in words is "seventy-eight million, four hundred five thousand, nine hundred twelve".