21555010453 has 4 divisors (see below), whose sum is σ = 21555330688. Its totient is φ = 21554690220.

The previous prime is 21555010429. The next prime is 21555010457. The reversal of 21555010453 is 35401055512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21555010453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21555010457) 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 in 3 ways as a sum of consecutive naturals, for example, 15783 + ... + 208228.

It is an arithmetic number, because the mean of its divisors is an integer number (5388832672).

Almost surely, 2^21555010453 is an apocalyptic number.

It is an amenable number.

21555010453 is a deficient number, since it is larger than the sum of its proper divisors (320235).

21555010453 is an equidigital number, since it uses as much as digits as its factorization.

21555010453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320234.

The product of its (nonzero) digits is 15000, while the sum is 31.

Adding to 21555010453 its reverse (35401055512), we get a palindrome (56956065965).

The spelling of 21555010453 in words is "twenty-one billion, five hundred fifty-five million, ten thousand, four hundred fifty-three".