78438558 has 32 divisors (see below), whose sum is σ = 173953152. Its totient is φ = 23378400.

The previous prime is 78438541. The next prime is 78438559. The reversal of 78438558 is 85583487.

It is a super-2 number, since 2×78438558² = 12305214762238728, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78438559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5716 + ... + 13767.

It is an arithmetic number, because the mean of its divisors is an integer number (5436036).

Almost surely, 2^78438558 is an apocalyptic number.

78438558 is an abundant number, since it is smaller than the sum of its proper divisors (95514594).

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

78438558 is a wasteful number, since it uses less digits than its factorization.

78438558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19560.

The product of its digits is 1075200, while the sum is 48.

The square root of 78438558 is about 8856.5545219346. The cubic root of 78438558 is about 428.0651449737.

Subtracting 78438558 from its reverse (85583487), we obtain a square (7144929 = 2673²).

The spelling of 78438558 in words is "seventy-eight million, four hundred thirty-eight thousand, five hundred fifty-eight".