21210101011 has 12 divisors (see below), whose sum is σ = 23367481816. Its totient is φ = 19237331520.

The previous prime is 21210100993. The next prime is 21210101041. The reversal of 21210101011 is 11010101212.

It is not a de Polignac number, because 21210101011 - 2⁷ = 21210100883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210101041) 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, 150021 + ... + 254806.

Almost surely, 2^21210101011 is an apocalyptic number.

21210101011 is a deficient number, since it is larger than the sum of its proper divisors (2157380805).

21210101011 is a wasteful number, since it uses less digits than its factorization.

21210101011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405282 (or 405271 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21210101011 its reverse (11010101212), we get a palindrome (32220202223).

It can be divided in two parts, 21210 and 101011, that added together give a palindrome (122221).

The spelling of 21210101011 in words is "twenty-one billion, two hundred ten million, one hundred one thousand, eleven".