65291661 has 6 divisors (see below), whose sum is σ = 94310190. Its totient is φ = 43527768.

The previous prime is 65291659. The next prime is 65291663. The reversal of 65291661 is 16619256.

65291661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (65291659) and next prime (65291663).

It can be written as a sum of positive squares in only one way, i.e., 56700900 + 8590761 = 7530^2 + 2931^2 .

It is not a de Polignac number, because 65291661 - 2¹ = 65291659 is a prime.

It is a super-2 number, since 2×65291661² = 8526001992277842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65291663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3627306 + ... + 3627323.

It is an arithmetic number, because the mean of its divisors is an integer number (15718365).

Almost surely, 2^65291661 is an apocalyptic number.

It is an amenable number.

65291661 is a deficient number, since it is larger than the sum of its proper divisors (29018529).

65291661 is a wasteful number, since it uses less digits than its factorization.

65291661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7254635 (or 7254632 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 65291661 is about 8080.3255503723. The cubic root of 65291661 is about 402.6730575343.

The spelling of 65291661 in words is "sixty-five million, two hundred ninety-one thousand, six hundred sixty-one".