66061987 has 2 divisors, whose sum is σ = 66061988. Its totient is φ = 66061986.

The previous prime is 66061969. The next prime is 66061999. The reversal of 66061987 is 78916066.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66061987 is a prime.

It is a super-2 number, since 2×66061987² = 8728372252776338, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66061927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33030993 + 33030994.

It is an arithmetic number, because the mean of its divisors is an integer number (33030994).

Almost surely, 2^66061987 is an apocalyptic number.

66061987 is a deficient number, since it is larger than the sum of its proper divisors (1).

66061987 is an equidigital number, since it uses as much as digits as its factorization.

66061987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 66061987 is about 8127.8525454144. The cubic root of 66061987 is about 404.2504798207.

The spelling of 66061987 in words is "sixty-six million, sixty-one thousand, nine hundred eighty-seven".