21011012211 has 16 divisors (see below), whose sum is σ = 32697990144. Its totient is φ = 11750839104.

The previous prime is 21011012177. The next prime is 21011012273. The reversal of 21011012211 is 11221011012.

It is not a de Polignac number, because 21011012211 - 2⁷ = 21011012083 is a prime.

It is a super-2 number, since 2×21011012211² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21011012291) 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, 10642890 + ... + 10644863.

It is an arithmetic number, because the mean of its divisors is an integer number (2043624384).

Almost surely, 2^21011012211 is an apocalyptic number.

21011012211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21011012211 is a deficient number, since it is larger than the sum of its proper divisors (11686977933).

21011012211 is a wasteful number, since it uses less digits than its factorization.

21011012211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21287810.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21011012211 its reverse (11221011012), we get a palindrome (32232023223).

The spelling of 21011012211 in words is "twenty-one billion, eleven million, twelve thousand, two hundred eleven".