81238061 has 2 divisors, whose sum is σ = 81238062. Its totient is φ = 81238060.

The previous prime is 81238039. The next prime is 81238067. The reversal of 81238061 is 16083218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59382436 + 21855625 = 7706^2 + 4675^2 .

It is a cyclic number.

It is not a de Polignac number, because 81238061 - 2⁶ = 81237997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81238067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40619030 + 40619031.

It is an arithmetic number, because the mean of its divisors is an integer number (40619031).

Almost surely, 2^81238061 is an apocalyptic number.

It is an amenable number.

81238061 is a deficient number, since it is larger than the sum of its proper divisors (1).

81238061 is an equidigital number, since it uses as much as digits as its factorization.

81238061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 81238061 is about 9013.2159077657. The cubic root of 81238061 is about 433.0983372135.

The spelling of 81238061 in words is "eighty-one million, two hundred thirty-eight thousand, sixty-one".