81049660 has 24 divisors (see below), whose sum is σ = 170797536. Its totient is φ = 32306880.

The previous prime is 81049621. The next prime is 81049679. The reversal of 81049660 is 6694018.

81049660 = T₂₀₅ + T₂₀₆ + ... + T₇₉₀.

It is a super-2 number, since 2×81049660² = 13138094772231200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1056 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (7116564).

Almost surely, 2^81049660 is an apocalyptic number.

It is an amenable number.

81049660 is an abundant number, since it is smaller than the sum of its proper divisors (89747876).

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

81049660 is a wasteful number, since it uses less digits than its factorization.

81049660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14133 (or 14131 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 81049660 is about 9002.7584661591. The cubic root of 81049660 is about 432.7632753907.

The spelling of 81049660 in words is "eighty-one million, forty-nine thousand, six hundred sixty".