66117251 has 2 divisors, whose sum is σ = 66117252. Its totient is φ = 66117250.

The previous prime is 66117239. The next prime is 66117257. The reversal of 66117251 is 15271166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66117251 - 2¹⁰ = 66116227 is a prime.

It is not a weakly prime, because it can be changed into another prime (66117257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33058625 + 33058626.

It is an arithmetic number, because the mean of its divisors is an integer number (33058626).

Almost surely, 2^66117251 is an apocalyptic number.

66117251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66117251 is an equidigital number, since it uses as much as digits as its factorization.

66117251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 29.

The square root of 66117251 is about 8131.2515026901. The cubic root of 66117251 is about 404.3631733317.

The spelling of 66117251 in words is "sixty-six million, one hundred seventeen thousand, two hundred fifty-one".