20356121 has 4 divisors (see below), whose sum is σ = 20701200. Its totient is φ = 20011044.

The previous prime is 20356117. The next prime is 20356139. The reversal of 20356121 is 12165302.

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 20356121 - 2² = 20356117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20356093 and 20356102.

It is not an unprimeable number, because it can be changed into a prime (20356111) 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, 172451 + ... + 172568.

It is an arithmetic number, because the mean of its divisors is an integer number (5175300).

Almost surely, 2^20356121 is an apocalyptic number.

It is an amenable number.

20356121 is a deficient number, since it is larger than the sum of its proper divisors (345079).

20356121 is an equidigital number, since it uses as much as digits as its factorization.

20356121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345078.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20356121 is about 4511.7758144660. The cubic root of 20356121 is about 273.0433945519.

The spelling of 20356121 in words is "twenty million, three hundred fifty-six thousand, one hundred twenty-one".