21025362665533 has 4 divisors (see below), whose sum is σ = 22262148704700. Its totient is φ = 19788576626368.

The previous prime is 21025362665507. The next prime is 21025362665557. The reversal of 21025362665533 is 33556626352012.

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 18171148394169 + 2854214271364 = 4262763^2 + 1689442^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21025362665533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21025362665563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 618393019558 + ... + 618393019591.

It is an arithmetic number, because the mean of its divisors is an integer number (5565537176175).

Almost surely, 2^{21025362665533} is an apocalyptic number.

It is an amenable number.

21025362665533 is a deficient number, since it is larger than the sum of its proper divisors (1236786039167).

21025362665533 is a wasteful number, since it uses less digits than its factorization.

21025362665533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236786039166.

The product of its (nonzero) digits is 5832000, while the sum is 49.

The spelling of 21025362665533 in words is "twenty-one trillion, twenty-five billion, three hundred sixty-two million, six hundred sixty-five thousand, five hundred thirty-three".