66978727 has 2 divisors, whose sum is σ = 66978728. Its totient is φ = 66978726.

The previous prime is 66978721. The next prime is 66978739. The reversal of 66978727 is 72787966.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66978727 is a prime.

It is a super-2 number, since 2×66978727² = 8972299741081058, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66978721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33489363 + 33489364.

It is an arithmetic number, because the mean of its divisors is an integer number (33489364).

Almost surely, 2^66978727 is an apocalyptic number.

66978727 is a deficient number, since it is larger than the sum of its proper divisors (1).

66978727 is an equidigital number, since it uses as much as digits as its factorization.

66978727 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 52.

The square root of 66978727 is about 8184.0532134145. The cubic root of 66978727 is about 406.1118197666. Note that the first 3 decimals are identical.

The spelling of 66978727 in words is "sixty-six million, nine hundred seventy-eight thousand, seven hundred twenty-seven".