65669621 has 2 divisors, whose sum is σ = 65669622. Its totient is φ = 65669620.

The previous prime is 65669599. The next prime is 65669627. The reversal of 65669621 is 12696656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65383396 + 286225 = 8086^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65669621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65669627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32834810 + 32834811.

It is an arithmetic number, because the mean of its divisors is an integer number (32834811).

Almost surely, 2^65669621 is an apocalyptic number.

It is an amenable number.

65669621 is a deficient number, since it is larger than the sum of its proper divisors (1).

65669621 is an equidigital number, since it uses as much as digits as its factorization.

65669621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 41.

The square root of 65669621 is about 8103.6794729308. The cubic root of 65669621 is about 403.4485602222.

The spelling of 65669621 in words is "sixty-five million, six hundred sixty-nine thousand, six hundred twenty-one".