81135637 has 8 divisors (see below), whose sum is σ = 88596000. Its totient is φ = 73689360.

The previous prime is 81135617. The next prime is 81135641. The reversal of 81135637 is 73653118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81135637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81135617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11239 + ... + 16987.

It is an arithmetic number, because the mean of its divisors is an integer number (11074500).

Almost surely, 2^81135637 is an apocalyptic number.

It is an amenable number.

81135637 is a deficient number, since it is larger than the sum of its proper divisors (7460363).

81135637 is a wasteful number, since it uses less digits than its factorization.

81135637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7043.

The product of its digits is 15120, while the sum is 34.

The square root of 81135637 is about 9007.5322369670. The cubic root of 81135637 is about 432.9162455546.

The spelling of 81135637 in words is "eighty-one million, one hundred thirty-five thousand, six hundred thirty-seven".