81408697 has 4 divisors (see below), whose sum is σ = 84034816. Its totient is φ = 78782580.

The previous prime is 81408643. The next prime is 81408737. The reversal of 81408697 is 79680418.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81408697 - 2¹⁵ = 81375929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81408617) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1313013 + ... + 1313074.

It is an arithmetic number, because the mean of its divisors is an integer number (21008704).

Almost surely, 2^81408697 is an apocalyptic number.

It is an amenable number.

81408697 is a deficient number, since it is larger than the sum of its proper divisors (2626119).

81408697 is a wasteful number, since it uses less digits than its factorization.

81408697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2626118.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 81408697 is about 9022.6768201017. The cubic root of 81408697 is about 433.4013580914.

The spelling of 81408697 in words is "eighty-one million, four hundred eight thousand, six hundred ninety-seven".