21345023353 has 4 divisors (see below), whose sum is σ = 22600612980. Its totient is φ = 20089433728.

The previous prime is 21345023327. The next prime is 21345023369. The reversal of 21345023353 is 35332054312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16980174864 + 4364848489 = 130308^2 + 66067^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345023353 - 2⁵ = 21345023321 is a prime.

It is a super-2 number, since 2×21345023353² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21345023383) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 627794788 + ... + 627794821.

It is an arithmetic number, because the mean of its divisors is an integer number (5650153245).

Almost surely, 2^21345023353 is an apocalyptic number.

It is an amenable number.

21345023353 is a deficient number, since it is larger than the sum of its proper divisors (1255589627).

21345023353 is a wasteful number, since it uses less digits than its factorization.

21345023353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255589626.

The product of its (nonzero) digits is 32400, while the sum is 31.

Adding to 21345023353 its reverse (35332054312), we get a palindrome (56677077665).

The spelling of 21345023353 in words is "twenty-one billion, three hundred forty-five million, twenty-three thousand, three hundred fifty-three".