81979046 has 4 divisors (see below), whose sum is σ = 122968572. Its totient is φ = 40989522.

The previous prime is 81979043. The next prime is 81979081. The reversal of 81979046 is 64097918.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 81978988 and 81979006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81979043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20494760 + ... + 20494763.

It is an arithmetic number, because the mean of its divisors is an integer number (30742143).

Almost surely, 2^81979046 is an apocalyptic number.

81979046 is a deficient number, since it is larger than the sum of its proper divisors (40989526).

81979046 is a wasteful number, since it uses less digits than its factorization.

81979046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40989525.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 81979046 is about 9054.2280731159. The cubic root of 81979046 is about 434.4111396255.

The spelling of 81979046 in words is "eighty-one million, nine hundred seventy-nine thousand, forty-six".