81647426 has 24 divisors (see below), whose sum is σ = 143098956. Its totient is φ = 34836480.

The previous prime is 81647407. The next prime is 81647437. The reversal of 81647426 is 62474618.

It can be written as a sum of positive squares in 2 ways, for example, as 78411025 + 3236401 = 8855^2 + 1799^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81647426.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21890 + ... + 25346.

Almost surely, 2^81647426 is an apocalyptic number.

81647426 is a deficient number, since it is larger than the sum of its proper divisors (61451530).

81647426 is a wasteful number, since it uses less digits than its factorization.

81647426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714 (or 3707 counting only the distinct ones).

The product of its digits is 64512, while the sum is 38.

The square root of 81647426 is about 9035.8965244186. The cubic root of 81647426 is about 433.8245909254.

The spelling of 81647426 in words is "eighty-one million, six hundred forty-seven thousand, four hundred twenty-six".