21021311452 has 12 divisors (see below), whose sum is σ = 36853344360. Its totient is φ = 10491784496.

The previous prime is 21021311417. The next prime is 21021311459. The reversal of 21021311452 is 25411312012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021311459) 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, 4715302 + ... + 4719757.

It is an arithmetic number, because the mean of its divisors is an integer number (3071112030).

Almost surely, 2^21021311452 is an apocalyptic number.

It is an amenable number.

21021311452 is a deficient number, since it is larger than the sum of its proper divisors (15832032908).

21021311452 is a wasteful number, since it uses less digits than its factorization.

21021311452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9435620 (or 9435618 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

Adding to 21021311452 its reverse (25411312012), we get a palindrome (46432623464).

The spelling of 21021311452 in words is "twenty-one billion, twenty-one million, three hundred eleven thousand, four hundred fifty-two".