66516419 has 2 divisors, whose sum is σ = 66516420. Its totient is φ = 66516418.

The previous prime is 66516409. The next prime is 66516469. The reversal of 66516419 is 91461566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66516419 - 2¹² = 66512323 is a prime.

It is a super-2 number, since 2×66516419² = 8848867993167122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66516409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33258209 + 33258210.

It is an arithmetic number, because the mean of its divisors is an integer number (33258210).

Almost surely, 2^66516419 is an apocalyptic number.

66516419 is a deficient number, since it is larger than the sum of its proper divisors (1).

66516419 is an equidigital number, since it uses as much as digits as its factorization.

66516419 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 66516419 is about 8155.7598664993. The cubic root of 66516419 is about 405.1752916956.

The spelling of 66516419 in words is "sixty-six million, five hundred sixteen thousand, four hundred nineteen".