81151579 has 2 divisors, whose sum is σ = 81151580. Its totient is φ = 81151578.

The previous prime is 81151571. The next prime is 81151627. The reversal of 81151579 is 97515118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81151579 - 2³ = 81151571 is a prime.

It is not a weakly prime, because it can be changed into another prime (81151571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40575789 + 40575790.

It is an arithmetic number, because the mean of its divisors is an integer number (40575790).

Almost surely, 2^81151579 is an apocalyptic number.

81151579 is a deficient number, since it is larger than the sum of its proper divisors (1).

81151579 is an equidigital number, since it uses as much as digits as its factorization.

81151579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12600, while the sum is 37.

The square root of 81151579 is about 9008.4171195610. The cubic root of 81151579 is about 432.9445976617.

The spelling of 81151579 in words is "eighty-one million, one hundred fifty-one thousand, five hundred seventy-nine".