20660401 has 4 divisors (see below), whose sum is σ = 21100032. Its totient is φ = 20220772.

The previous prime is 20660399. The next prime is 20660473. The reversal of 20660401 is 10406602.

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 20660401 - 2¹ = 20660399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20660501) 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, 219745 + ... + 219838.

It is an arithmetic number, because the mean of its divisors is an integer number (5275008).

Almost surely, 2^20660401 is an apocalyptic number.

It is an amenable number.

20660401 is a deficient number, since it is larger than the sum of its proper divisors (439631).

20660401 is an equidigital number, since it uses as much as digits as its factorization.

20660401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439630.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 20660401 is about 4545.3713819665. The cubic root of 20660401 is about 274.3971410778.

The spelling of 20660401 in words is "twenty million, six hundred sixty thousand, four hundred one".