65991251 has 2 divisors, whose sum is σ = 65991252. Its totient is φ = 65991250.

The previous prime is 65991241. The next prime is 65991259. The reversal of 65991251 is 15219956.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 65991251 - 2⁶ = 65991187 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p_3895643 and since 65991251 and 3895643 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (65991259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32995625 + 32995626.

It is an arithmetic number, because the mean of its divisors is an integer number (32995626).

Almost surely, 2^65991251 is an apocalyptic number.

65991251 is a deficient number, since it is larger than the sum of its proper divisors (1).

65991251 is an equidigital number, since it uses as much as digits as its factorization.

65991251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24300, while the sum is 38.

The square root of 65991251 is about 8123.4999230627. The cubic root of 65991251 is about 404.1061442989.

The spelling of 65991251 in words is "sixty-five million, nine hundred ninety-one thousand, two hundred fifty-one".