21002155323533 has 4 divisors (see below), whose sum is σ = 21004559149980. Its totient is φ = 20999751497088.

The previous prime is 21002155323481. The next prime is 21002155323577. The reversal of 21002155323533 is 33532355120012.

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 15964164088324 + 5037991235209 = 3995518^2 + 2244547^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002155323533 - 2⁶ = 21002155323469 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002155323493 and 21002155323502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002155323133) 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, 1201900118 + ... + 1201917591.

It is an arithmetic number, because the mean of its divisors is an integer number (5251139787495).

Almost surely, 2^{21002155323533} is an apocalyptic number.

It is an amenable number.

21002155323533 is a deficient number, since it is larger than the sum of its proper divisors (2403826447).

21002155323533 is an equidigital number, since it uses as much as digits as its factorization.

21002155323533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2403826446.

The product of its (nonzero) digits is 81000, while the sum is 35.

The spelling of 21002155323533 in words is "twenty-one trillion, two billion, one hundred fifty-five million, three hundred twenty-three thousand, five hundred thirty-three".