21110000021 has 8 divisors (see below), whose sum is σ = 23030752800. Its totient is φ = 19189524240.

The previous prime is 21110000003. The next prime is 21110000057. The reversal of 21110000021 is 12000001112.

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 21110000021 - 2¹⁸ = 21109737877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21109999963 and 21110000008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110000081) 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, 110375 + ... + 233243.

It is an arithmetic number, because the mean of its divisors is an integer number (2878844100).

Almost surely, 2^21110000021 is an apocalyptic number.

It is an amenable number.

21110000021 is a deficient number, since it is larger than the sum of its proper divisors (1920752779).

21110000021 is a wasteful number, since it uses less digits than its factorization.

21110000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138499.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21110000021 its reverse (12000001112), we get a palindrome (33110001133).

The spelling of 21110000021 in words is "twenty-one billion, one hundred ten million, twenty-one", and thus it is an aban number.