66402251 has 2 divisors, whose sum is σ = 66402252. Its totient is φ = 66402250.

The previous prime is 66402239. The next prime is 66402319. The reversal of 66402251 is 15220466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66402251 - 2¹⁰ = 66401227 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66402251.

It is not a weakly prime, because it can be changed into another prime (66402151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33201125 + 33201126.

It is an arithmetic number, because the mean of its divisors is an integer number (33201126).

Almost surely, 2^66402251 is an apocalyptic number.

66402251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66402251 is an equidigital number, since it uses as much as digits as its factorization.

66402251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 66402251 is about 8148.7576353699. The cubic root of 66402251 is about 404.9433462388.

The spelling of 66402251 in words is "sixty-six million, four hundred two thousand, two hundred fifty-one".