21001005011 has 6 divisors (see below), whose sum is σ = 24429740580. Its totient is φ = 18000861396.

The previous prime is 21001004987. The next prime is 21001005037. The reversal of 21001005011 is 11050010012.

It is not a de Polignac number, because 21001005011 - 2¹⁰ = 21001003987 is a prime.

It is a super-2 number, since 2×21001005011² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21001004983 and 21001005001.

It is not an unprimeable number, because it can be changed into a prime (21001055011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214295921 + ... + 214296018.

It is an arithmetic number, because the mean of its divisors is an integer number (4071623430).

Almost surely, 2^21001005011 is an apocalyptic number.

21001005011 is a deficient number, since it is larger than the sum of its proper divisors (3428735569).

21001005011 is an equidigital number, since it uses as much as digits as its factorization.

21001005011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428591953 (or 428591946 counting only the distinct ones).

The product of its (nonzero) digits is 10, while the sum is 11.

Adding to 21001005011 its reverse (11050010012), we get a palindrome (32051015023).

The spelling of 21001005011 in words is "twenty-one billion, one million, five thousand, eleven".