81000052101 has 24 divisors (see below), whose sum is σ = 119044092960. Its totient is φ = 53057580576.

The previous prime is 81000052097. The next prime is 81000052153. The reversal of 81000052101 is 10125000018.

It is not a de Polignac number, because 81000052101 - 2² = 81000052097 is a prime.

It is a super-2 number, since 2×81000052101² (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 (81000052181) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1025515 + ... + 1101671.

It is an arithmetic number, because the mean of its divisors is an integer number (4960170540).

Almost surely, 2^81000052101 is an apocalyptic number.

It is an amenable number.

81000052101 is a deficient number, since it is larger than the sum of its proper divisors (38044040859).

81000052101 is a wasteful number, since it uses less digits than its factorization.

81000052101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78225 (or 78222 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

Adding to 81000052101 its reverse (10125000018), we get a palindrome (91125052119).

The spelling of 81000052101 in words is "eighty-one billion, fifty-two thousand, one hundred one".