20400511 has 8 divisors (see below), whose sum is σ = 21123200. Its totient is φ = 19681920.

The previous prime is 20400481. The next prime is 20400521. The reversal of 20400511 is 11500402.

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 20400511 - 2²¹ = 18303359 is a prime.

It is a super-2 number, since 2×20400511² = 832361698122242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20400491 and 20400500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400521) 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, 11875 + ... + 13483.

It is an arithmetic number, because the mean of its divisors is an integer number (2640400).

Almost surely, 2^20400511 is an apocalyptic number.

20400511 is a deficient number, since it is larger than the sum of its proper divisors (722689).

20400511 is a wasteful number, since it uses less digits than its factorization.

20400511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2049.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 20400511 is about 4516.6924845511. The cubic root of 20400511 is about 273.2417230504.

Adding to 20400511 its reverse (11500402), we get a palindrome (31900913).

The spelling of 20400511 in words is "twenty million, four hundred thousand, five hundred eleven".