78166425 has 48 divisors (see below), whose sum is σ = 138419712. Its totient is φ = 38784000.

The previous prime is 78166409. The next prime is 78166433. The reversal of 78166425 is 52466187.

It is not a de Polignac number, because 78166425 - 2⁴ = 78166409 is a prime.

It is a super-2 number, since 2×78166425² = 12219979994561250, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 128472 + ... + 129078.

It is an arithmetic number, because the mean of its divisors is an integer number (2883744).

Almost surely, 2^78166425 is an apocalyptic number.

78166425 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

78166425 is a deficient number, since it is larger than the sum of its proper divisors (60253287).

78166425 is a wasteful number, since it uses less digits than its factorization.

78166425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738 (or 733 counting only the distinct ones).

The product of its digits is 80640, while the sum is 39.

The square root of 78166425 is about 8841.1778061523. The cubic root of 78166425 is about 427.5695314556.

It can be divided in two parts, 7816 and 6425, that added together give a palindrome (14241).

The spelling of 78166425 in words is "seventy-eight million, one hundred sixty-six thousand, four hundred twenty-five".