20666427 has 4 divisors (see below), whose sum is σ = 27555240. Its totient is φ = 13777616.

The previous prime is 20666413. The next prime is 20666447. The reversal of 20666427 is 72466602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20666427 - 2⁶ = 20666363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20666447) 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, 3444402 + ... + 3444407.

It is an arithmetic number, because the mean of its divisors is an integer number (6888810).

Almost surely, 2^20666427 is an apocalyptic number.

20666427 is a deficient number, since it is larger than the sum of its proper divisors (6888813).

20666427 is an equidigital number, since it uses as much as digits as its factorization.

20666427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6888812.

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 20666427 is about 4546.0342057666. The cubic root of 20666427 is about 274.4238162044.

The spelling of 20666427 in words is "twenty million, six hundred sixty-six thousand, four hundred twenty-seven".