21154437133 has 2 divisors, whose sum is σ = 21154437134. Its totient is φ = 21154437132.

The previous prime is 21154437103. The next prime is 21154437193. The reversal of 21154437133 is 33173445112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21153666249 + 770884 = 145443^2 + 878^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21154437133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21154437103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10577218566 + 10577218567.

It is an arithmetic number, because the mean of its divisors is an integer number (10577218567).

Almost surely, 2^21154437133 is an apocalyptic number.

It is an amenable number.

21154437133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21154437133 is an equidigital number, since it uses as much as digits as its factorization.

21154437133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The spelling of 21154437133 in words is "twenty-one billion, one hundred fifty-four million, four hundred thirty-seven thousand, one hundred thirty-three".