211011021 has 32 divisors (see below), whose sum is σ = 356469120. Its totient is φ = 122211072.

The previous prime is 211011011. The next prime is 211011071. The reversal of 211011021 is 120110112.

It is a happy number.

It is not a de Polignac number, because 211011021 - 2¹⁸ = 210748877 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 211010994 and 211011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211011011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11715 + ... + 23648.

It is an arithmetic number, because the mean of its divisors is an integer number (11139660).

Almost surely, 2^211011021 is an apocalyptic number.

It is an amenable number.

211011021 is a deficient number, since it is larger than the sum of its proper divisors (145458099).

211011021 is a wasteful number, since it uses less digits than its factorization.

211011021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35402 (or 35396 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 211011021 is about 14526.2183998452. The cubic root of 211011021 is about 595.3445463436.

Adding to 211011021 its reverse (120110112), we get a palindrome (331121133).

Subtracting from 211011021 its reverse (120110112), we obtain a palindrome (90900909).

It can be divided in two parts, 21101 and 1021, that added together give a palindrome (22122).

The spelling of 211011021 in words is "two hundred eleven million, eleven thousand, twenty-one".