81876638 has 4 divisors (see below), whose sum is σ = 122814960. Its totient is φ = 40938318.

The previous prime is 81876629. The next prime is 81876647. The reversal of 81876638 is 83667818.

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

It is an interprime number because it is at equal distance from previous prime (81876629) and next prime (81876647).

It is a junction number, because it is equal to n+sod(n) for n = 81876592 and 81876601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20469158 + ... + 20469161.

It is an arithmetic number, because the mean of its divisors is an integer number (30703740).

Almost surely, 2^81876638 is an apocalyptic number.

81876638 is a deficient number, since it is larger than the sum of its proper divisors (40938322).

81876638 is a wasteful number, since it uses less digits than its factorization.

81876638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40938321.

The product of its digits is 387072, while the sum is 47.

The square root of 81876638 is about 9048.5710474085. The cubic root of 81876638 is about 434.2301758490.

The spelling of 81876638 in words is "eighty-one million, eight hundred seventy-six thousand, six hundred thirty-eight".