20400533121511 has 8 divisors (see below), whose sum is σ = 20419406604864. Its totient is φ = 20381660325120.

The previous prime is 20400533121503. The next prime is 20400533121613. The reversal of 20400533121511 is 11512133500402.

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 20400533121511 - 2³ = 20400533121503 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 20400533121511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400533121211) 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, 74002771 + ... + 74277931.

It is an arithmetic number, because the mean of its divisors is an integer number (2552425825608).

Almost surely, 2^{20400533121511} is an apocalyptic number.

20400533121511 is a deficient number, since it is larger than the sum of its proper divisors (18873483353).

20400533121511 is a wasteful number, since it uses less digits than its factorization.

20400533121511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343481.

The product of its (nonzero) digits is 3600, while the sum is 28.

Adding to 20400533121511 its reverse (11512133500402), we get a palindrome (31912666621913).

The spelling of 20400533121511 in words is "twenty trillion, four hundred billion, five hundred thirty-three million, one hundred twenty-one thousand, five hundred eleven".