6661401 has 4 divisors (see below), whose sum is σ = 8881872. Its totient is φ = 4440932.

The previous prime is 6661379. The next prime is 6661409. The reversal of 6661401 is 1041666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6661401 - 2⁶ = 6661337 is a prime.

It is a D-number.

6661401 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6661409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1110231 + ... + 1110236.

It is an arithmetic number, because the mean of its divisors is an integer number (2220468).

Almost surely, 2^6661401 is an apocalyptic number.

It is an amenable number.

6661401 is a deficient number, since it is larger than the sum of its proper divisors (2220471).

6661401 is a wasteful number, since it uses less digits than its factorization.

6661401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2220470.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 6661401 is about 2580.9690040758. The cubic root of 6661401 is about 188.1576409038.

The spelling of 6661401 in words is "six million, six hundred sixty-one thousand, four hundred one".