81051589 has 2 divisors, whose sum is σ = 81051590. Its totient is φ = 81051588.

The previous prime is 81051569. The next prime is 81051599. The reversal of 81051589 is 98515018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64931364 + 16120225 = 8058^2 + 4015^2 .

It is a cyclic number.

It is not a de Polignac number, because 81051589 - 2¹³ = 81043397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81051539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40525794 + 40525795.

It is an arithmetic number, because the mean of its divisors is an integer number (40525795).

Almost surely, 2^81051589 is an apocalyptic number.

It is an amenable number.

81051589 is a deficient number, since it is larger than the sum of its proper divisors (1).

81051589 is an equidigital number, since it uses as much as digits as its factorization.

81051589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 37.

The square root of 81051589 is about 9002.8655993522. The cubic root of 81051589 is about 432.7667086510.

The spelling of 81051589 in words is "eighty-one million, fifty-one thousand, five hundred eighty-nine".