81457699 has 2 divisors, whose sum is σ = 81457700. Its totient is φ = 81457698.

The previous prime is 81457681. The next prime is 81457711. The reversal of 81457699 is 99675418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81457699 - 2¹¹ = 81455651 is a prime.

It is not a weakly prime, because it can be changed into another prime (81457679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40728849 + 40728850.

It is an arithmetic number, because the mean of its divisors is an integer number (40728850).

Almost surely, 2^81457699 is an apocalyptic number.

81457699 is a deficient number, since it is larger than the sum of its proper divisors (1).

81457699 is an equidigital number, since it uses as much as digits as its factorization.

81457699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 49.

The square root of 81457699 is about 9025.3919028483. The cubic root of 81457699 is about 433.4882991449.

The spelling of 81457699 in words is "eighty-one million, four hundred fifty-seven thousand, six hundred ninety-nine".