21000011001 has 16 divisors (see below), whose sum is σ = 28333005120. Its totient is φ = 13834059200.

The previous prime is 21000010991. The next prime is 21000011027. The reversal of 21000011001 is 10011000012.

It is a cyclic number.

It is not a de Polignac number, because 21000011001 - 2³³ = 12410076409 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21000011051) 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, 86146 + ... + 222308.

It is an arithmetic number, because the mean of its divisors is an integer number (1770812820).

Almost surely, 2^21000011001 is an apocalyptic number.

It is an amenable number.

21000011001 is a deficient number, since it is larger than the sum of its proper divisors (7332994119).

21000011001 is a wasteful number, since it uses less digits than its factorization.

21000011001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136776.

The product of its (nonzero) digits is 2, while the sum is 6.

Adding to 21000011001 its reverse (10011000012), we get a palindrome (31011011013).

The spelling of 21000011001 in words is "twenty-one billion, eleven thousand, one".