78145566 has 32 divisors (see below), whose sum is σ = 166367520. Its totient is φ = 24385536.

The previous prime is 78145553. The next prime is 78145567. The reversal of 78145566 is 66554187.

It is a super-2 number, since 2×78145566² = 12213458970920712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78145567) 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, 18150 + ... + 22038.

It is an arithmetic number, because the mean of its divisors is an integer number (5198985).

Almost surely, 2^78145566 is an apocalyptic number.

78145566 is an abundant number, since it is smaller than the sum of its proper divisors (88221954).

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

78145566 is a wasteful number, since it uses less digits than its factorization.

78145566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4108.

The product of its digits is 201600, while the sum is 42.

The square root of 78145566 is about 8839.9980769229. The cubic root of 78145566 is about 427.5314952344.

The spelling of 78145566 in words is "seventy-eight million, one hundred forty-five thousand, five hundred sixty-six".