81542248201 has 2 divisors, whose sum is σ = 81542248202. Its totient is φ = 81542248200.

The previous prime is 81542248171. The next prime is 81542248213. The reversal of 81542248201 is 10284224518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68474328976 + 13067919225 = 261676^2 + 114315^2 .

It is a cyclic number.

It is not a de Polignac number, because 81542248201 - 2²⁹ = 81005377289 is a prime.

It is not a weakly prime, because it can be changed into another prime (81542248261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40771124100 + 40771124101.

It is an arithmetic number, because the mean of its divisors is an integer number (40771124101).

Almost surely, 2^81542248201 is an apocalyptic number.

It is an amenable number.

81542248201 is a deficient number, since it is larger than the sum of its proper divisors (1).

81542248201 is an equidigital number, since it uses as much as digits as its factorization.

81542248201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40960, while the sum is 37.

The spelling of 81542248201 in words is "eighty-one billion, five hundred forty-two million, two hundred forty-eight thousand, two hundred one".