81002035591 has 8 divisors (see below), whose sum is σ = 85773888144. Its totient is φ = 76230963840.

The previous prime is 81002035577. The next prime is 81002035613. The reversal of 81002035591 is 19553020018.

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-81002035591 is a prime.

It is a super-2 number, since 2×81002035591² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81002035561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25536 + ... + 403306.

It is an arithmetic number, because the mean of its divisors is an integer number (10721736018).

Almost surely, 2^81002035591 is an apocalyptic number.

81002035591 is a deficient number, since it is larger than the sum of its proper divisors (4771852553).

81002035591 is a wasteful number, since it uses less digits than its factorization.

81002035591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390401.

The product of its (nonzero) digits is 10800, while the sum is 34.

The spelling of 81002035591 in words is "eighty-one billion, two million, thirty-five thousand, five hundred ninety-one".