20521313121 has 8 divisors (see below), whose sum is σ = 27364748704. Its totient is φ = 13679376480.

The previous prime is 20521313117. The next prime is 20521313149. The reversal of 20521313121 is 12131312502.

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

It is not a de Polignac number, because 20521313121 - 2² = 20521313117 is a prime.

It is a super-2 number, since 2×20521313121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20521313191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342391 + ... + 397836.

It is an arithmetic number, because the mean of its divisors is an integer number (3420593588).

Almost surely, 2^20521313121 is an apocalyptic number.

It is an amenable number.

20521313121 is a deficient number, since it is larger than the sum of its proper divisors (6843435583).

20521313121 is an equidigital number, since it uses as much as digits as its factorization.

20521313121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749471.

The product of its (nonzero) digits is 360, while the sum is 21.

Adding to 20521313121 its reverse (12131312502), we get a palindrome (32652625623).

The spelling of 20521313121 in words is "twenty billion, five hundred twenty-one million, three hundred thirteen thousand, one hundred twenty-one".