21311010021 has 8 divisors (see below), whose sum is σ = 32473920064. Its totient is φ = 12177720000.

The previous prime is 21311010011. The next prime is 21311010073. The reversal of 21311010021 is 12001011312.

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

It is not a de Polignac number, because 21311010021 - 2¹⁰ = 21311008997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21311009979 and 21311010006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311010011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 507404980 + ... + 507405021.

It is an arithmetic number, because the mean of its divisors is an integer number (4059240008).

Almost surely, 2^21311010021 is an apocalyptic number.

21311010021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21311010021 is a deficient number, since it is larger than the sum of its proper divisors (11162910043).

21311010021 is a wasteful number, since it uses less digits than its factorization.

21311010021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014810011.

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21311010021 its reverse (12001011312), we get a palindrome (33312021333).

The spelling of 21311010021 in words is "twenty-one billion, three hundred eleven million, ten thousand, twenty-one".