66978701 has 2 divisors, whose sum is σ = 66978702. Its totient is φ = 66978700.

The previous prime is 66978689. The next prime is 66978721. The reversal of 66978701 is 10787966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36893476 + 30085225 = 6074^2 + 5485^2 .

It is a cyclic number.

It is not a de Polignac number, because 66978701 - 2¹⁴ = 66962317 is a prime.

It is a super-2 number, since 2×66978701² = 8972292775294802, 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, 33489350 + 33489351.

It is an arithmetic number, because the mean of its divisors is an integer number (33489351).

Almost surely, 2^66978701 is an apocalyptic number.

It is an amenable number.

66978701 is a deficient number, since it is larger than the sum of its proper divisors (1).

66978701 is an equidigital number, since it uses as much as digits as its factorization.

66978701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 66978701 is about 8184.0516249594. The cubic root of 66978701 is about 406.1117672180. Note that the first 3 decimals are identical.

The spelling of 66978701 in words is "sixty-six million, nine hundred seventy-eight thousand, seven hundred one".