21324350553 has 16 divisors (see below), whose sum is σ = 31054964736. Its totient is φ = 12908129040.

The previous prime is 21324350549. The next prime is 21324350581. The reversal of 21324350553 is 35505342312.

It is not a de Polignac number, because 21324350553 - 2² = 21324350549 is a prime.

It is a super-3 number, since 3×21324350553³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21324350053) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 365425 + ... + 419742.

It is an arithmetic number, because the mean of its divisors is an integer number (1940935296).

Almost surely, 2^21324350553 is an apocalyptic number.

It is an amenable number.

21324350553 is a deficient number, since it is larger than the sum of its proper divisors (9730614183).

21324350553 is a wasteful number, since it uses less digits than its factorization.

21324350553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786004.

The product of its (nonzero) digits is 54000, while the sum is 33.

Adding to 21324350553 its reverse (35505342312), we get a palindrome (56829692865).

The spelling of 21324350553 in words is "twenty-one billion, three hundred twenty-four million, three hundred fifty thousand, five hundred fifty-three".