21135356601 has 4 divisors (see below), whose sum is σ = 28180475472. Its totient is φ = 14090237732.

The previous prime is 21135356569. The next prime is 21135356621. The reversal of 21135356601 is 10665353112.

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 not a de Polignac number, because 21135356601 - 2⁵ = 21135356569 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21135356621) 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, 3522559431 + ... + 3522559436.

It is an arithmetic number, because the mean of its divisors is an integer number (7045118868).

Almost surely, 2^21135356601 is an apocalyptic number.

It is an amenable number.

21135356601 is a deficient number, since it is larger than the sum of its proper divisors (7045118871).

21135356601 is an equidigital number, since it uses as much as digits as its factorization.

21135356601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7045118870.

The product of its (nonzero) digits is 16200, while the sum is 33.

The spelling of 21135356601 in words is "twenty-one billion, one hundred thirty-five million, three hundred fifty-six thousand, six hundred one".