20400440121 has 24 divisors (see below), whose sum is σ = 29625916320. Its totient is φ = 13527216576.

The previous prime is 20400440119. The next prime is 20400440131. The reversal of 20400440121 is 12104400402.

20400440121 is a `hidden beast` number, since 204 + 0 + 0 + 440 + 1 + 21 = 666.

It is not a de Polignac number, because 20400440121 - 2¹ = 20400440119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20400440094 and 20400440103.

It is not an unprimeable number, because it can be changed into a prime (20400440131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2132070 + ... + 2141616.

It is an arithmetic number, because the mean of its divisors is an integer number (1234413180).

Almost surely, 2^20400440121 is an apocalyptic number.

It is an amenable number.

20400440121 is a deficient number, since it is larger than the sum of its proper divisors (9225476199).

20400440121 is a wasteful number, since it uses less digits than its factorization.

20400440121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10805 (or 10802 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 20400440121 its reverse (12104400402), we get a palindrome (32504840523).

The spelling of 20400440121 in words is "twenty billion, four hundred million, four hundred forty thousand, one hundred twenty-one".