21054340353 has 16 divisors (see below), whose sum is σ = 29727976320. Its totient is φ = 13208699136.

The previous prime is 21054340337. The next prime is 21054340357. The reversal of 21054340353 is 35304345012.

It is not a de Polignac number, because 21054340353 - 2⁴ = 21054340337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21054340353.

It is not an unprimeable number, because it can be changed into a prime (21054340357) 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, 395028 + ... + 445146.

It is an arithmetic number, because the mean of its divisors is an integer number (1857998520).

Almost surely, 2^21054340353 is an apocalyptic number.

It is an amenable number.

21054340353 is a deficient number, since it is larger than the sum of its proper divisors (8673635967).

21054340353 is a wasteful number, since it uses less digits than its factorization.

21054340353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58376.

The product of its (nonzero) digits is 21600, while the sum is 30.

Adding to 21054340353 its reverse (35304345012), we get a palindrome (56358685365).

The spelling of 21054340353 in words is "twenty-one billion, fifty-four million, three hundred forty thousand, three hundred fifty-three".