78171942 has 16 divisors (see below), whose sum is σ = 156969792. Its totient is φ = 25953000.

The previous prime is 78171937. The next prime is 78171943. The reversal of 78171942 is 24917187.

It is a super-2 number, since 2×78171942² = 12221705032102728, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78171942.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78171943) 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 7 ways as a sum of consecutive naturals, for example, 24448 + ... + 27459.

It is an arithmetic number, because the mean of its divisors is an integer number (9810612).

Almost surely, 2^78171942 is an apocalyptic number.

78171942 is an abundant number, since it is smaller than the sum of its proper divisors (78797850).

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

78171942 is a wasteful number, since it uses less digits than its factorization.

78171942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52163.

The product of its digits is 28224, while the sum is 39.

The square root of 78171942 is about 8841.4898065880. The cubic root of 78171942 is about 427.5795905298.

The spelling of 78171942 in words is "seventy-eight million, one hundred seventy-one thousand, nine hundred forty-two".