81185901350401 has 16 divisors (see below), whose sum is σ = 85239347967360. Its totient is φ = 77218659745920.

The previous prime is 81185901350399. The next prime is 81185901350431. The reversal of 81185901350401 is 10405310958118.

It is a cyclic number.

It is not a de Polignac number, because 81185901350401 - 2¹ = 81185901350399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81185901350431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21556315 + ... + 25040896.

It is an arithmetic number, because the mean of its divisors is an integer number (5327459247960).

Almost surely, 2^{81185901350401} is an apocalyptic number.

It is an amenable number.

81185901350401 is a deficient number, since it is larger than the sum of its proper divisors (4053446616959).

81185901350401 is a wasteful number, since it uses less digits than its factorization.

81185901350401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46598136.

The product of its (nonzero) digits is 172800, while the sum is 46.

The spelling of 81185901350401 in words is "eighty-one trillion, one hundred eighty-five billion, nine hundred one million, three hundred fifty thousand, four hundred one".