66045521 has 2 divisors, whose sum is σ = 66045522. Its totient is φ = 66045520.

The previous prime is 66045517. The next prime is 66045533. The reversal of 66045521 is 12554066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34281025 + 31764496 = 5855^2 + 5636^2 .

It is a cyclic number.

It is not a de Polignac number, because 66045521 - 2² = 66045517 is a prime.

It is a super-2 number, since 2×66045521² = 8724021688322882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66047521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33022760 + 33022761.

It is an arithmetic number, because the mean of its divisors is an integer number (33022761).

Almost surely, 2^66045521 is an apocalyptic number.

It is an amenable number.

66045521 is a deficient number, since it is larger than the sum of its proper divisors (1).

66045521 is an equidigital number, since it uses as much as digits as its factorization.

66045521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 66045521 is about 8126.8395456044. The cubic root of 66045521 is about 404.2168904510.

Adding to 66045521 its reverse (12554066), we get a palindrome (78599587).

It can be divided in two parts, 66045 and 521, that added together give a palindrome (66566).

The spelling of 66045521 in words is "sixty-six million, forty-five thousand, five hundred twenty-one".