21001000033 has 16 divisors (see below), whose sum is σ = 23310314496. Its totient is φ = 18796613760.

The previous prime is 21001000019. The next prime is 21001000037. The reversal of 21001000033 is 33000010012.

It is a cyclic number.

It is not a de Polignac number, because 21001000033 - 2⁵ = 21001000001 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21000999983 and 21001000019.

It is not an unprimeable number, because it can be changed into a prime (21001000037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33985 + ... + 207742.

It is an arithmetic number, because the mean of its divisors is an integer number (1456894656).

Almost surely, 2^21001000033 is an apocalyptic number.

It is an amenable number.

21001000033 is a deficient number, since it is larger than the sum of its proper divisors (2309314463).

21001000033 is a wasteful number, since it uses less digits than its factorization.

21001000033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241944.

The product of its (nonzero) digits is 18, while the sum is 10.

Adding to 21001000033 its reverse (33000010012), we get a palindrome (54001010045).

The spelling of 21001000033 in words is "twenty-one billion, one million, thirty-three", and thus it is an aban number and an uban number.