81448640842 has 16 divisors (see below), whose sum is σ = 129645593280. Its totient is φ = 38293464352.

The previous prime is 81448640839. The next prime is 81448640869. The reversal of 81448640842 is 24804684418.

It is a super-2 number, since 2×81448640842² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15002563 + ... + 15007990.

It is an arithmetic number, because the mean of its divisors is an integer number (8102849580).

Almost surely, 2^81448640842 is an apocalyptic number.

81448640842 is a deficient number, since it is larger than the sum of its proper divisors (48196952438).

81448640842 is a wasteful number, since it uses less digits than its factorization.

81448640842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30010637.

The product of its (nonzero) digits is 1572864, while the sum is 49.

The spelling of 81448640842 in words is "eighty-one billion, four hundred forty-eight million, six hundred forty thousand, eight hundred forty-two".