81601715 has 16 divisors (see below), whose sum is σ = 107448768. Its totient is φ = 59120256.

The previous prime is 81601643. The next prime is 81601727. The reversal of 81601715 is 51710618.

It is not a de Polignac number, because 81601715 - 2¹⁸ = 81339571 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8399 + ... + 15288.

It is an arithmetic number, because the mean of its divisors is an integer number (6715548).

Almost surely, 2^81601715 is an apocalyptic number.

81601715 is a deficient number, since it is larger than the sum of its proper divisors (25847053).

81601715 is a wasteful number, since it uses less digits than its factorization.

81601715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23758.

The product of its (nonzero) digits is 1680, while the sum is 29.

The square root of 81601715 is about 9033.3667588557. The cubic root of 81601715 is about 433.7436156933.

The spelling of 81601715 in words is "eighty-one million, six hundred one thousand, seven hundred fifteen".