81422005061 has 4 divisors (see below), whose sum is σ = 81455418252. Its totient is φ = 81388591872.

The previous prime is 81422005057. The next prime is 81422005073. The reversal of 81422005061 is 16050022418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42433528036 + 38988477025 = 205994^2 + 197455^2 .

It is a cyclic number.

It is not a de Polignac number, because 81422005061 - 2² = 81422005057 is a prime.

It is a super-2 number, since 2×81422005061² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81422005031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16702940 + ... + 16707813.

It is an arithmetic number, because the mean of its divisors is an integer number (20363854563).

Almost surely, 2^81422005061 is an apocalyptic number.

It is an amenable number.

81422005061 is a deficient number, since it is larger than the sum of its proper divisors (33413191).

81422005061 is a wasteful number, since it uses less digits than its factorization.

81422005061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33413190.

The product of its (nonzero) digits is 3840, while the sum is 29.

Adding to 81422005061 its reverse (16050022418), we get a palindrome (97472027479).

The spelling of 81422005061 in words is "eighty-one billion, four hundred twenty-two million, five thousand, sixty-one".