21430286791021 has 8 divisors (see below), whose sum is σ = 21463286363288. Its totient is φ = 21397288968000.

The previous prime is 21430286791009. The next prime is 21430286791061. The reversal of 21430286791021 is 12019768203412.

It can be written as a sum of positive squares in 4 ways, for example, as 9359255304100 + 12071031486921 = 3059290^2 + 3474339^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21430286791021 - 2⁹ = 21430286790509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430286791061) 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 7 ways as a sum of consecutive naturals, for example, 25243111 + ... + 26078251.

It is an arithmetic number, because the mean of its divisors is an integer number (2682910795411).

Almost surely, 2^{21430286791021} is an apocalyptic number.

It is an amenable number.

21430286791021 is a deficient number, since it is larger than the sum of its proper divisors (32999572267).

21430286791021 is an equidigital number, since it uses as much as digits as its factorization.

21430286791021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 874623.

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 21430286791021 in words is "twenty-one trillion, four hundred thirty billion, two hundred eighty-six million, seven hundred ninety-one thousand, twenty-one".