81879748 has 6 divisors (see below), whose sum is σ = 143289566. Its totient is φ = 40939872.

The previous prime is 81879719. The next prime is 81879767. The reversal of 81879748 is 84797818.

It can be written as a sum of positive squares in only one way, i.e., 78996544 + 2883204 = 8888^2 + 1698^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81879695 and 81879704.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10234965 + ... + 10234972.

Almost surely, 2^81879748 is an apocalyptic number.

It is an amenable number.

81879748 is a deficient number, since it is larger than the sum of its proper divisors (61409818).

81879748 is a wasteful number, since it uses less digits than its factorization.

81879748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20469941 (or 20469939 counting only the distinct ones).

The product of its digits is 903168, while the sum is 52.

The square root of 81879748 is about 9048.7428961155. The cubic root of 81879748 is about 434.2356737085.

The spelling of 81879748 in words is "eighty-one million, eight hundred seventy-nine thousand, seven hundred forty-eight".