66551519 has 2 divisors, whose sum is σ = 66551520. Its totient is φ = 66551518.

The previous prime is 66551503. The next prime is 66551521. The reversal of 66551519 is 91515566.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66551519 - 2⁴ = 66551503 is a prime.

It is a super-2 number, since 2×66551519² = 8858209362414722, which contains 22 as substring.

Together with 66551521, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66551119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33275759 + 33275760.

It is an arithmetic number, because the mean of its divisors is an integer number (33275760).

Almost surely, 2^66551519 is an apocalyptic number.

66551519 is a deficient number, since it is larger than the sum of its proper divisors (1).

66551519 is an equidigital number, since it uses as much as digits as its factorization.

66551519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40500, while the sum is 38.

The square root of 66551519 is about 8157.9114361459. The cubic root of 66551519 is about 405.2465480467.

The spelling of 66551519 in words is "sixty-six million, five hundred fifty-one thousand, five hundred nineteen".