78171982 has 16 divisors (see below), whose sum is σ = 136010880. Its totient is φ = 33001848.

The previous prime is 78171971. The next prime is 78171983. The reversal of 78171982 is 28917187.

It is a happy number.

It is a super-2 number, since 2×78171982² = 12221717539616648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78171983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40732 + ... + 42607.

It is an arithmetic number, because the mean of its divisors is an integer number (8500680).

Almost surely, 2^78171982 is an apocalyptic number.

78171982 is a deficient number, since it is larger than the sum of its proper divisors (57838898).

78171982 is a wasteful number, since it uses less digits than its factorization.

78171982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83415.

The product of its digits is 56448, while the sum is 43.

The square root of 78171982 is about 8841.4920686500. The cubic root of 78171982 is about 427.5796634596.

The spelling of 78171982 in words is "seventy-eight million, one hundred seventy-one thousand, nine hundred eighty-two".