20400133 has 4 divisors (see below), whose sum is σ = 21969388. Its totient is φ = 18830880.

The previous prime is 20400101. The next prime is 20400151. The reversal of 20400133 is 33100402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9628609 + 10771524 = 3103^2 + 3282^2 .

It is a cyclic number.

It is not a de Polignac number, because 20400133 - 2⁵ = 20400101 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 1569241 = 20400133 / (2 + 0 + 4 + 0 + 0 + 1 + 3 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400173) 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, 784608 + ... + 784633.

It is an arithmetic number, because the mean of its divisors is an integer number (5492347).

Almost surely, 2^20400133 is an apocalyptic number.

It is an amenable number.

20400133 is a deficient number, since it is larger than the sum of its proper divisors (1569255).

20400133 is a wasteful number, since it uses less digits than its factorization.

20400133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1569254.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 20400133 is about 4516.6506395780. The cubic root of 20400133 is about 273.2400354128.

Adding to 20400133 its reverse (33100402), we get a palindrome (53500535).

The spelling of 20400133 in words is "twenty million, four hundred thousand, one hundred thirty-three".