20311212121 has 8 divisors (see below), whose sum is σ = 20986207488. Its totient is φ = 19637454000.

The previous prime is 20311212107. The next prime is 20311212127. The reversal of 20311212121 is 12121211302.

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

It is a cyclic number.

It is not a de Polignac number, because 20311212121 - 2⁷ = 20311211993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20311212095 and 20311212104.

It is not an unprimeable number, because it can be changed into a prime (20311212127) 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, 275875 + ... + 341656.

It is an arithmetic number, because the mean of its divisors is an integer number (2623275936).

Almost surely, 2^20311212121 is an apocalyptic number.

It is an amenable number.

20311212121 is a deficient number, since it is larger than the sum of its proper divisors (674995367).

20311212121 is a wasteful number, since it uses less digits than its factorization.

20311212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618623.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20311212121 its reverse (12121211302), we get a palindrome (32432423423).

The spelling of 20311212121 in words is "twenty billion, three hundred eleven million, two hundred twelve thousand, one hundred twenty-one".