20787841 has 4 divisors (see below), whose sum is σ = 20830000. Its totient is φ = 20745684.

The previous prime is 20787839. The next prime is 20787857. The reversal of 20787841 is 14878702.

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 20787841 - 2¹ = 20787839 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20787841.

It is not an unprimeable number, because it can be changed into a prime (20787541) 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, 20331 + ... + 21328.

It is an arithmetic number, because the mean of its divisors is an integer number (5207500).

Almost surely, 2^20787841 is an apocalyptic number.

It is an amenable number.

20787841 is a deficient number, since it is larger than the sum of its proper divisors (42159).

20787841 is an equidigital number, since it uses as much as digits as its factorization.

20787841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42158.

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 20787841 is about 4559.3684869727. The cubic root of 20787841 is about 274.9601749491.

The spelling of 20787841 in words is "twenty million, seven hundred eighty-seven thousand, eight hundred forty-one".