81615052592501 has 2 divisors, whose sum is σ = 81615052592502. Its totient is φ = 81615052592500.

The previous prime is 81615052592461. The next prime is 81615052592597. The reversal of 81615052592501 is 10529525051618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68061279005476 + 13553773587025 = 8249926^2 + 3681545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81615052592501 is a prime.

It is a super-2 number, since 2×81615052592501² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81615052592501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81615052522501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40807526296250 + 40807526296251.

It is an arithmetic number, because the mean of its divisors is an integer number (40807526296251).

Almost surely, 2^{81615052592501} is an apocalyptic number.

It is an amenable number.

81615052592501 is a deficient number, since it is larger than the sum of its proper divisors (1).

81615052592501 is an equidigital number, since it uses as much as digits as its factorization.

81615052592501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080000, while the sum is 50.

The spelling of 81615052592501 in words is "eighty-one trillion, six hundred fifteen billion, fifty-two million, five hundred ninety-two thousand, five hundred one".