20001955 has 8 divisors (see below), whose sum is σ = 24026400. Its totient is φ = 15985536.

The previous prime is 20001937. The next prime is 20001959. The reversal of 20001955 is 55910002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001955 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20001959) 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 7 ways as a sum of consecutive naturals, for example, 8331 + ... + 10459.

It is an arithmetic number, because the mean of its divisors is an integer number (3003300).

Almost surely, 2^20001955 is an apocalyptic number.

20001955 is a deficient number, since it is larger than the sum of its proper divisors (4024445).

20001955 is a wasteful number, since it uses less digits than its factorization.

20001955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4013.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 20001955 is about 4472.3545253032. The cubic root of 20001955 is about 271.4506058487.

Adding to 20001955 its reverse (55910002), we get a palindrome (75911957).

The spelling of 20001955 in words is "twenty million, one thousand, nine hundred fifty-five".