81061696 has 14 divisors (see below), whose sum is σ = 160856930. Its totient is φ = 40530816.

The previous prime is 81061681. The next prime is 81061697. The reversal of 81061696 is 69616018.

It can be written as a sum of positive squares in only one way, i.e., 68558400 + 12503296 = 8280^2 + 3536^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81061697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633231 + ... + 633358.

Almost surely, 2^81061696 is an apocalyptic number.

It is an amenable number.

81061696 is a deficient number, since it is larger than the sum of its proper divisors (79795234).

81061696 is a wasteful number, since it uses less digits than its factorization.

81061696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1266601 (or 1266591 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 81061696 is about 9003.4269031297. The cubic root of 81061696 is about 432.7846963359.

The spelling of 81061696 in words is "eighty-one million, sixty-one thousand, six hundred ninety-six".