65612321 has 4 divisors (see below), whose sum is σ = 65632944. Its totient is φ = 65591700.

The previous prime is 65612291. The next prime is 65612381. The reversal of 65612321 is 12321656.

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 65612321 - 2⁶ = 65612257 is a prime.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65612381) 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, 4415 + ... + 12276.

It is an arithmetic number, because the mean of its divisors is an integer number (16408236).

Almost surely, 2^65612321 is an apocalyptic number.

It is an amenable number.

65612321 is a deficient number, since it is larger than the sum of its proper divisors (20623).

65612321 is a wasteful number, since it uses less digits than its factorization.

65612321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20622.

The product of its digits is 2160, while the sum is 26.

The square root of 65612321 is about 8100.1432703379. The cubic root of 65612321 is about 403.3311831196.

Adding to 65612321 its reverse (12321656), we get a palindrome (77933977).

The spelling of 65612321 in words is "sixty-five million, six hundred twelve thousand, three hundred twenty-one".