20051591 has 8 divisors (see below), whose sum is σ = 23018880. Its totient is φ = 17110008.

The previous prime is 20051587. The next prime is 20051597. The reversal of 20051591 is 19515002.

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

It is a cyclic number.

It is not a de Polignac number, because 20051591 - 2² = 20051587 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20051597) 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, 4721 + ... + 7898.

It is an arithmetic number, because the mean of its divisors is an integer number (2877360).

Almost surely, 2^20051591 is an apocalyptic number.

20051591 is a deficient number, since it is larger than the sum of its proper divisors (2967289).

20051591 is a wasteful number, since it uses less digits than its factorization.

20051591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12853.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 20051591 is about 4477.9002891981. The cubic root of 20051591 is about 271.6749604571.

Adding to 20051591 its reverse (19515002), we get a palindrome (39566593).

The spelling of 20051591 in words is "twenty million, fifty-one thousand, five hundred ninety-one".