66921269 has 2 divisors, whose sum is σ = 66921270. Its totient is φ = 66921268.

The previous prime is 66921247. The next prime is 66921301. The reversal of 66921269 is 96212966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66178225 + 743044 = 8135^2 + 862^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66921269 is a prime.

It is a super-2 number, since 2×66921269² = 8956912489140722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66921229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33460634 + 33460635.

It is an arithmetic number, because the mean of its divisors is an integer number (33460635).

Almost surely, 2^66921269 is an apocalyptic number.

It is an amenable number.

66921269 is a deficient number, since it is larger than the sum of its proper divisors (1).

66921269 is an equidigital number, since it uses as much as digits as its factorization.

66921269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 41.

The square root of 66921269 is about 8180.5420969518. The cubic root of 66921269 is about 405.9956582645.

The spelling of 66921269 in words is "sixty-six million, nine hundred twenty-one thousand, two hundred sixty-nine".