20211012121 has 4 divisors (see below), whose sum is σ = 20211340212. Its totient is φ = 20210684032.

The previous prime is 20211012119. The next prime is 20211012169. The reversal of 20211012121 is 12121011202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5488587225 + 14722424896 = 74085^2 + 121336^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211012121 - 2¹ = 20211012119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20211012181) 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, 40756 + ... + 205141.

It is an arithmetic number, because the mean of its divisors is an integer number (5052835053).

Almost surely, 2^20211012121 is an apocalyptic number.

It is an amenable number.

20211012121 is a deficient number, since it is larger than the sum of its proper divisors (328091).

20211012121 is an equidigital number, since it uses as much as digits as its factorization.

20211012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328090.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 20211012121 its reverse (12121011202), we get a palindrome (32332023323).

The spelling of 20211012121 in words is "twenty billion, two hundred eleven million, twelve thousand, one hundred twenty-one".