21213513021 has 8 divisors (see below), whose sum is σ = 29260018080. Its totient is φ = 13654674992.

The previous prime is 21213512987. The next prime is 21213513023. The reversal of 21213513021 is 12031531212.

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 21213513021 - 2¹⁹ = 21212988733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213513023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121916655 + ... + 121916828.

It is an arithmetic number, because the mean of its divisors is an integer number (3657502260).

Almost surely, 2^21213513021 is an apocalyptic number.

It is an amenable number.

21213513021 is a deficient number, since it is larger than the sum of its proper divisors (8046505059).

21213513021 is a wasteful number, since it uses less digits than its factorization.

21213513021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243833515.

The product of its (nonzero) digits is 360, while the sum is 21.

The spelling of 21213513021 in words is "twenty-one billion, two hundred thirteen million, five hundred thirteen thousand, twenty-one".