20100220121 has 4 divisors (see below), whose sum is σ = 20134462992. Its totient is φ = 20065977252.

The previous prime is 20100220109. The next prime is 20100220139. The reversal of 20100220121 is 12102200102.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-20100220121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20100228121) 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, 17120555 + ... + 17121728.

It is an arithmetic number, because the mean of its divisors is an integer number (5033615748).

Almost surely, 2^20100220121 is an apocalyptic number.

It is an amenable number.

20100220121 is a deficient number, since it is larger than the sum of its proper divisors (34242871).

20100220121 is an equidigital number, since it uses as much as digits as its factorization.

20100220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34242870.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20100220121 its reverse (12102200102), we get a palindrome (32202420223).

The spelling of 20100220121 in words is "twenty billion, one hundred million, two hundred twenty thousand, one hundred twenty-one".