81477982 has 8 divisors (see below), whose sum is σ = 126159552. Its totient is φ = 39424800.

The previous prime is 81477973. The next prime is 81477989. The reversal of 81477982 is 28977418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81477989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 657019 + ... + 657142.

It is an arithmetic number, because the mean of its divisors is an integer number (15769944).

Almost surely, 2^81477982 is an apocalyptic number.

81477982 is a deficient number, since it is larger than the sum of its proper divisors (44681570).

81477982 is a wasteful number, since it uses less digits than its factorization.

81477982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1314194.

The product of its digits is 225792, while the sum is 46.

The square root of 81477982 is about 9026.5154960261. The cubic root of 81477982 is about 433.5242757463.

It can be divided in two parts, 8147 and 7982, that added together give a square (16129 = 127²).

The spelling of 81477982 in words is "eighty-one million, four hundred seventy-seven thousand, nine hundred eighty-two".