81950101 has 2 divisors, whose sum is σ = 81950102. Its totient is φ = 81950100.

The previous prime is 81950053. The next prime is 81950107. The reversal of 81950101 is 10105918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44422225 + 37527876 = 6665^2 + 6126^2 .

It is a cyclic number.

It is not a de Polignac number, because 81950101 - 2⁹ = 81949589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81950107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40975050 + 40975051.

It is an arithmetic number, because the mean of its divisors is an integer number (40975051).

Almost surely, 2^81950101 is an apocalyptic number.

It is an amenable number.

81950101 is a deficient number, since it is larger than the sum of its proper divisors (1).

81950101 is an equidigital number, since it uses as much as digits as its factorization.

81950101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 25.

The square root of 81950101 is about 9052.6295074967. The cubic root of 81950101 is about 434.3600065974.

The spelling of 81950101 in words is "eighty-one million, nine hundred fifty thousand, one hundred one".