78400086 has 16 divisors (see below), whose sum is σ = 156891504. Its totient is φ = 26118144.

The previous prime is 78400043. The next prime is 78400087. The reversal of 78400086 is 68000487.

It is a super-2 number, since 2×78400086² = 12293146969614792, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78400087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13206 + ... + 18198.

It is an arithmetic number, because the mean of its divisors is an integer number (9805719).

Almost surely, 2^78400086 is an apocalyptic number.

78400086 is an abundant number, since it is smaller than the sum of its proper divisors (78491418).

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

78400086 is a wasteful number, since it uses less digits than its factorization.

78400086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7615.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 78400086 is about 8854.3823048251. The cubic root of 78400086 is about 427.9951487207.

The spelling of 78400086 in words is "seventy-eight million, four hundred thousand, eighty-six".