21000535345 has 4 divisors (see below), whose sum is σ = 25200642420. Its totient is φ = 16800428272.

The previous prime is 21000535321. The next prime is 21000535363. The reversal of 21000535345 is 54353500012.

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 8596812961 + 12403722384 = 92719^2 + 111372^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000535345 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2100053530 + ... + 2100053539.

It is an arithmetic number, because the mean of its divisors is an integer number (6300160605).

Almost surely, 2^21000535345 is an apocalyptic number.

It is an amenable number.

21000535345 is a deficient number, since it is larger than the sum of its proper divisors (4200107075).

21000535345 is an equidigital number, since it uses as much as digits as its factorization.

21000535345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4200107074.

The product of its (nonzero) digits is 9000, while the sum is 28.

It can be divided in two parts, 210005 and 35345, that added together give a triangular number (245350 = T₇₀₀).

The spelling of 21000535345 in words is "twenty-one billion, five hundred thirty-five thousand, three hundred forty-five".