21431100133 has 4 divisors (see below), whose sum is σ = 22691753100. Its totient is φ = 20170447168.

The previous prime is 21431100109. The next prime is 21431100157. The reversal of 21431100133 is 33100113412.

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

It is an interprime number because it is at equal distance from previous prime (21431100109) and next prime (21431100157).

It can be written as a sum of positive squares in 2 ways, for example, as 6694839684 + 14736260449 = 81822^2 + 121393^2 .

It is a cyclic number.

It is not a de Polignac number, because 21431100133 - 2²⁹ = 20894229221 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 21431100133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431100533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 630326458 + ... + 630326491.

It is an arithmetic number, because the mean of its divisors is an integer number (5672938275).

Almost surely, 2^21431100133 is an apocalyptic number.

It is an amenable number.

21431100133 is a deficient number, since it is larger than the sum of its proper divisors (1260652967).

21431100133 is a wasteful number, since it uses less digits than its factorization.

21431100133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260652966.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21431100133 its reverse (33100113412), we get a palindrome (54531213545).

The spelling of 21431100133 in words is "twenty-one billion, four hundred thirty-one million, one hundred thousand, one hundred thirty-three".