21321898851 has 8 divisors (see below), whose sum is σ = 31013671104. Its totient is φ = 12922362920.

The previous prime is 21321898849. The next prime is 21321898889. The reversal of 21321898851 is 15889812312.

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 21321898851 - 2¹ = 21321898849 is a prime.

It is a super-2 number, since 2×21321898851² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21321898851.

It is not an unprimeable number, because it can be changed into a prime (21321898891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323059041 + ... + 323059106.

It is an arithmetic number, because the mean of its divisors is an integer number (3876708888).

Almost surely, 2^21321898851 is an apocalyptic number.

21321898851 is a deficient number, since it is larger than the sum of its proper divisors (9691772253).

21321898851 is a wasteful number, since it uses less digits than its factorization.

21321898851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646118161.

The product of its digits is 276480, while the sum is 48.

The spelling of 21321898851 in words is "twenty-one billion, three hundred twenty-one million, eight hundred ninety-eight thousand, eight hundred fifty-one".