81700648 has 16 divisors (see below), whose sum is σ = 153360180. Its totient is φ = 40804608.

The previous prime is 81700637. The next prime is 81700649. The reversal of 81700648 is 84600718.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 56520324 + 25180324 = 7518^2 + 5018^2 .

It is not an unprimeable number, because it can be changed into a prime (81700649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2590 + ... + 13042.

Almost surely, 2^81700648 is an apocalyptic number.

It is an amenable number.

81700648 is a deficient number, since it is larger than the sum of its proper divisors (71659532).

81700648 is a wasteful number, since it uses less digits than its factorization.

81700648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11436 (or 11432 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 81700648 is about 9038.8410761557. The cubic root of 81700648 is about 433.9188335262.

The spelling of 81700648 in words is "eighty-one million, seven hundred thousand, six hundred forty-eight".