21311313121 has 8 divisors (see below), whose sum is σ = 25637670080. Its totient is φ = 17305427088.

The previous prime is 21311313097. The next prime is 21311313131. The reversal of 21311313121 is 12131311312.

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

It is not a de Polignac number, because 21311313121 - 2⁷ = 21311312993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311313131) 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, 80117586 + ... + 80117851.

It is an arithmetic number, because the mean of its divisors is an integer number (3204708760).

Almost surely, 2^21311313121 is an apocalyptic number.

It is an amenable number.

21311313121 is a deficient number, since it is larger than the sum of its proper divisors (4326356959).

21311313121 is a wasteful number, since it uses less digits than its factorization.

21311313121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160235463.

The product of its digits is 108, while the sum is 19.

Adding to 21311313121 its reverse (12131311312), we get a palindrome (33442624433).

The spelling of 21311313121 in words is "twenty-one billion, three hundred eleven million, three hundred thirteen thousand, one hundred twenty-one".