81472889 has 2 divisors, whose sum is σ = 81472890. Its totient is φ = 81472888.

The previous prime is 81472879. The next prime is 81472901. The reversal of 81472889 is 98827418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79512889 + 1960000 = 8917^2 + 1400^2 .

It is a cyclic number.

It is not a de Polignac number, because 81472889 - 2¹⁶ = 81407353 is a prime.

It is not a weakly prime, because it can be changed into another prime (81472879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40736444 + 40736445.

It is an arithmetic number, because the mean of its divisors is an integer number (40736445).

Almost surely, 2^81472889 is an apocalyptic number.

It is an amenable number.

81472889 is a deficient number, since it is larger than the sum of its proper divisors (1).

81472889 is an equidigital number, since it uses as much as digits as its factorization.

81472889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 258048, while the sum is 47.

The square root of 81472889 is about 9026.2333783256. The cubic root of 81472889 is about 433.5152426918.

The spelling of 81472889 in words is "eighty-one million, four hundred seventy-two thousand, eight hundred eighty-nine".