65881601 has 4 divisors (see below), whose sum is σ = 65921604. Its totient is φ = 65841600.

The previous prime is 65881589. The next prime is 65881619. The reversal of 65881601 is 10618856.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58125376 + 7756225 = 7624^2 + 2785^2 .

It is a cyclic number.

It is not a de Polignac number, because 65881601 - 2¹⁸ = 65619457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65881661) 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, 17420 + ... + 20861.

It is an arithmetic number, because the mean of its divisors is an integer number (16480401).

Almost surely, 2^65881601 is an apocalyptic number.

It is an amenable number.

65881601 is a deficient number, since it is larger than the sum of its proper divisors (40003).

65881601 is a wasteful number, since it uses less digits than its factorization.

65881601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40002.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 65881601 is about 8116.7481789199. The cubic root of 65881601 is about 403.8822014658.

The spelling of 65881601 in words is "sixty-five million, eight hundred eighty-one thousand, six hundred one".