81606448 has 40 divisors (see below), whose sum is σ = 197130240. Its totient is φ = 31794240.

The previous prime is 81606431. The next prime is 81606457. The reversal of 81606448 is 84460618.

It is a super-2 number, since 2×81606448² = 13319224710353408, which contains 22 as substring.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

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, 31888 + ... + 34351.

It is an arithmetic number, because the mean of its divisors is an integer number (4928256).

Almost surely, 2^81606448 is an apocalyptic number.

81606448 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81606448 is an abundant number, since it is smaller than the sum of its proper divisors (115523792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81606448 is a wasteful number, since it uses less digits than its factorization.

81606448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66265 (or 66259 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 81606448 is about 9033.6287282575. The cubic root of 81606448 is about 433.7520014192.

The spelling of 81606448 in words is "eighty-one million, six hundred six thousand, four hundred forty-eight".