19905427 has 4 divisors (see below), whose sum is σ = 19914840. Its totient is φ = 19896016.

The previous prime is 19905409. The next prime is 19905437. The reversal of 19905427 is 72450991.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19905427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19905437) 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, 108 + ... + 6310.

It is an arithmetic number, because the mean of its divisors is an integer number (4978710).

Almost surely, 2^19905427 is an apocalyptic number.

19905427 is a deficient number, since it is larger than the sum of its proper divisors (9413).

19905427 is an equidigital number, since it uses as much as digits as its factorization.

19905427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9412.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 19905427 is about 4461.5498428237. The cubic root of 19905427 is about 271.0132344676.

The spelling of 19905427 in words is "nineteen million, nine hundred five thousand, four hundred twenty-seven".