66401677 has 12 divisors (see below), whose sum is σ = 72930780. Its totient is φ = 60176256.

The previous prime is 66401669. The next prime is 66401681. The reversal of 66401677 is 77610466.

It can be written as a sum of positive squares in 2 ways, for example, as 43639236 + 22762441 = 6606^2 + 4771^2 .

It is not a de Polignac number, because 66401677 - 2³ = 66401669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66401617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 180748 + ... + 181114.

It is an arithmetic number, because the mean of its divisors is an integer number (6077565).

Almost surely, 2^66401677 is an apocalyptic number.

It is an amenable number.

66401677 is a deficient number, since it is larger than the sum of its proper divisors (6529103).

66401677 is an equidigital number, since it uses as much as digits as its factorization.

66401677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 66401677 is about 8148.7224152010. The cubic root of 66401677 is about 404.9421794202.

The spelling of 66401677 in words is "sixty-six million, four hundred one thousand, six hundred seventy-seven".