66402601 has 4 divisors (see below), whose sum is σ = 66418900. Its totient is φ = 66386304.

The previous prime is 66402569. The next prime is 66402607. The reversal of 66402601 is 10620466.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2322576 + 64080025 = 1524^2 + 8005^2 .

It is a cyclic number.

It is not a de Polignac number, because 66402601 - 2⁵ = 66402569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66402607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3985 + ... + 12193.

It is an arithmetic number, because the mean of its divisors is an integer number (16604725).

Almost surely, 2^66402601 is an apocalyptic number.

It is an amenable number.

66402601 is a deficient number, since it is larger than the sum of its proper divisors (16299).

66402601 is an equidigital number, since it uses as much as digits as its factorization.

66402601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16298.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 66402601 is about 8148.7791110080. The cubic root of 66402601 is about 404.9440577103.

The spelling of 66402601 in words is "sixty-six million, four hundred two thousand, six hundred one".