65256561 has 12 divisors (see below), whose sum is σ = 94839888. Its totient is φ = 43236504.

The previous prime is 65256547. The next prime is 65256617. The reversal of 65256561 is 16565256.

It is a happy number.

It is not a de Polignac number, because 65256561 - 2¹³ = 65248369 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (65256361) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20775 + ... + 23708.

It is an arithmetic number, because the mean of its divisors is an integer number (7903324).

Almost surely, 2^65256561 is an apocalyptic number.

It is an amenable number.

65256561 is a deficient number, since it is larger than the sum of its proper divisors (29583327).

65256561 is a wasteful number, since it uses less digits than its factorization.

65256561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44652 (or 44649 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 65256561 is about 8078.1533161980. The cubic root of 65256561 is about 402.6008872266.

The spelling of 65256561 in words is "sixty-five million, two hundred fifty-six thousand, five hundred sixty-one".