81602663651 has 8 divisors (see below), whose sum is σ = 81721977408. Its totient is φ = 81483400000.

The previous prime is 81602663617. The next prime is 81602663699. The reversal of 81602663651 is 15636620618.

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-81602663651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81602683651) 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, 4285151 + ... + 4304151.

It is an arithmetic number, because the mean of its divisors is an integer number (10215247176).

Almost surely, 2^81602663651 is an apocalyptic number.

81602663651 is a deficient number, since it is larger than the sum of its proper divisors (119313757).

81602663651 is a wasteful number, since it uses less digits than its factorization.

81602663651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25053.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 81602663651 in words is "eighty-one billion, six hundred two million, six hundred sixty-three thousand, six hundred fifty-one".