20400223121 has 4 divisors (see below), whose sum is σ = 20401267200. Its totient is φ = 20399179044.

The previous prime is 20400223117. The next prime is 20400223153. The reversal of 20400223121 is 12132200402.

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 not a de Polignac number, because 20400223121 - 2² = 20400223117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20400223121.

It is not an unprimeable number, because it can be changed into a prime (20400223111) 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, 492161 + ... + 531998.

It is an arithmetic number, because the mean of its divisors is an integer number (5100316800).

Almost surely, 2^20400223121 is an apocalyptic number.

It is an amenable number.

20400223121 is a deficient number, since it is larger than the sum of its proper divisors (1044079).

20400223121 is a wasteful number, since it uses less digits than its factorization.

20400223121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044078.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 20400223121 its reverse (12132200402), we get a palindrome (32532423523).

The spelling of 20400223121 in words is "twenty billion, four hundred million, two hundred twenty-three thousand, one hundred twenty-one".