20788121 has 4 divisors (see below), whose sum is σ = 20832000. Its totient is φ = 20744244.

The previous prime is 20788063. The next prime is 20788133. The reversal of 20788121 is 12188702.

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 20788121 - 2²² = 16593817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20788921) 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, 21221 + ... + 22178.

It is an arithmetic number, because the mean of its divisors is an integer number (5208000).

Almost surely, 2^20788121 is an apocalyptic number.

It is an amenable number.

20788121 is a deficient number, since it is larger than the sum of its proper divisors (43879).

20788121 is an equidigital number, since it uses as much as digits as its factorization.

20788121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43878.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 20788121 is about 4559.3991928762. The cubic root of 20788121 is about 274.9614094609.

The spelling of 20788121 in words is "twenty million, seven hundred eighty-eight thousand, one hundred twenty-one".