20643427 has 8 divisors (see below), whose sum is σ = 24353792. Its totient is φ = 17123400.

The previous prime is 20643421. The next prime is 20643431. The reversal of 20643427 is 72434602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20643427 - 2¹⁹ = 20119139 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20643395 and 20643404.

It is not an unprimeable number, because it can be changed into a prime (20643421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47349 + ... + 47782.

It is an arithmetic number, because the mean of its divisors is an integer number (3044224).

Almost surely, 2^20643427 is an apocalyptic number.

20643427 is a deficient number, since it is larger than the sum of its proper divisors (3710365).

20643427 is an equidigital number, since it uses as much as digits as its factorization.

20643427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95169.

The product of its (nonzero) digits is 8064, while the sum is 28.

The square root of 20643427 is about 4543.5038241428. The cubic root of 20643427 is about 274.3219748508.

The spelling of 20643427 in words is "twenty million, six hundred forty-three thousand, four hundred twenty-seven".