21352000021 has 12 divisors (see below), whose sum is σ = 24349872960. Its totient is φ = 18566951480.

The previous prime is 21352000003. The next prime is 21352000069. The reversal of 21352000021 is 12000025312.

It is not a de Polignac number, because 21352000021 - 2²¹ = 21349902869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21351999959 and 21352000004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21352000001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1828861 + ... + 1840498.

It is an arithmetic number, because the mean of its divisors is an integer number (2029156080).

Almost surely, 2^21352000021 is an apocalyptic number.

It is an amenable number.

21352000021 is a deficient number, since it is larger than the sum of its proper divisors (2997872939).

21352000021 is a wasteful number, since it uses less digits than its factorization.

21352000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3669416 (or 3669393 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

Adding to 21352000021 its reverse (12000025312), we get a palindrome (33352025333).

The spelling of 21352000021 in words is "twenty-one billion, three hundred fifty-two million, twenty-one", and thus it is an aban number.