78400512 has 132 divisors (see below), whose sum is σ = 232473696. Its totient is φ = 25436160.

The previous prime is 78400501. The next prime is 78400523. The reversal of 78400512 is 21500487.

It is an interprime number because it is at equal distance from previous prime (78400501) and next prime (78400523).

It is a super-2 number, since 2×78400512² = 12293280563724288, which contains 22 as substring.

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, 433062 + ... + 433242.

Almost surely, 2^78400512 is an apocalyptic number.

78400512 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 78400512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116236848).

78400512 is an abundant number, since it is smaller than the sum of its proper divisors (154073184).

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

78400512 is a wasteful number, since it uses less digits than its factorization.

78400512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 78400512 is about 8854.4063606772. The cubic root of 78400512 is about 427.9959239138.

Adding to 78400512 its product of nonzero digits (2240), we get a cube (78402752 = 428³).

Adding to 78400512 its reverse (21500487), we get a palindrome (99900999).

The spelling of 78400512 in words is "seventy-eight million, four hundred thousand, five hundred twelve".