66503251 has 2 divisors, whose sum is σ = 66503252. Its totient is φ = 66503250.

The previous prime is 66503233. The next prime is 66503257. The reversal of 66503251 is 15230566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66503251 - 2⁷ = 66503123 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66503257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33251625 + 33251626.

It is an arithmetic number, because the mean of its divisors is an integer number (33251626).

Almost surely, 2^66503251 is an apocalyptic number.

66503251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66503251 is an equidigital number, since it uses as much as digits as its factorization.

66503251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 66503251 is about 8154.9525443132. The cubic root of 66503251 is about 405.1485529322.

The spelling of 66503251 in words is "sixty-six million, five hundred three thousand, two hundred fifty-one".