78135728 has 20 divisors (see below), whose sum is σ = 165150888. Its totient is φ = 35516160.

The previous prime is 78135719. The next prime is 78135763. The reversal of 78135728 is 82753187.

It is a super-2 number, since 2×78135728² = 12210383980179968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221801 + ... + 222152.

Almost surely, 2^78135728 is an apocalyptic number.

It is an amenable number.

78135728 is an abundant number, since it is smaller than the sum of its proper divisors (87015160).

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

78135728 is a wasteful number, since it uses less digits than its factorization.

78135728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443972 (or 443966 counting only the distinct ones).

The product of its digits is 94080, while the sum is 41.

The square root of 78135728 is about 8839.4416113236. The cubic root of 78135728 is about 427.5135533703.

The spelling of 78135728 in words is "seventy-eight million, one hundred thirty-five thousand, seven hundred twenty-eight".