20400231121 has 2 divisors, whose sum is σ = 20400231122. Its totient is φ = 20400231120.

The previous prime is 20400231029. The next prime is 20400231127. The reversal of 20400231121 is 12113200402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13249161025 + 7151070096 = 115105^2 + 84564^2 .

It is a cyclic number.

It is not a de Polignac number, because 20400231121 - 2²¹ = 20398133969 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20400231095 and 20400231104.

It is not a weakly prime, because it can be changed into another prime (20400231127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200115560 + 10200115561.

It is an arithmetic number, because the mean of its divisors is an integer number (10200115561).

Almost surely, 2^20400231121 is an apocalyptic number.

It is an amenable number.

20400231121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400231121 is an equidigital number, since it uses as much as digits as its factorization.

20400231121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 20400231121 its reverse (12113200402), we get a palindrome (32513431523).

The spelling of 20400231121 in words is "twenty billion, four hundred million, two hundred thirty-one thousand, one hundred twenty-one".