78128534 has 32 divisors (see below), whose sum is σ = 134561952. Its totient is φ = 33696000.

The previous prime is 78128521. The next prime is 78128537. The reversal of 78128534 is 43582187.

It is a super-2 number, since 2×78128534² = 12208135649978312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78128537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32204 + ... + 34544.

It is an arithmetic number, because the mean of its divisors is an integer number (4205061).

Almost surely, 2^78128534 is an apocalyptic number.

78128534 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

78128534 is a deficient number, since it is larger than the sum of its proper divisors (56433418).

78128534 is a wasteful number, since it uses less digits than its factorization.

78128534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2432.

The product of its digits is 53760, while the sum is 38.

The square root of 78128534 is about 8839.0346758003. The cubic root of 78128534 is about 427.5004324973.

The spelling of 78128534 in words is "seventy-eight million, one hundred twenty-eight thousand, five hundred thirty-four".