65640761 has 4 divisors (see below), whose sum is σ = 65678592. Its totient is φ = 65602932.

The previous prime is 65640749. The next prime is 65640787. The reversal of 65640761 is 16704656.

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 65640761 - 2²² = 61446457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65640721) 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, 16181 + ... + 19826.

It is an arithmetic number, because the mean of its divisors is an integer number (16419648).

Almost surely, 2^65640761 is an apocalyptic number.

It is an amenable number.

65640761 is a deficient number, since it is larger than the sum of its proper divisors (37831).

65640761 is a wasteful number, since it uses less digits than its factorization.

65640761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37830.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 65640761 is about 8101.8986046482. The cubic root of 65640761 is about 403.3894500311.

The spelling of 65640761 in words is "sixty-five million, six hundred forty thousand, seven hundred sixty-one".