211102021 has 8 divisors (see below), whose sum is σ = 231630840. Its totient is φ = 191186112.

The previous prime is 211102009. The next prime is 211102079. The reversal of 211102021 is 120201112.

It can be written as a sum of positive squares in 4 ways, for example, as 39125025 + 171976996 = 6255^2 + 13114^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 211102021 - 2⁷ = 211101893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211101989 and 211102007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211102081) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152506 + ... + 153883.

It is an arithmetic number, because the mean of its divisors is an integer number (28953855).

Almost surely, 2^211102021 is an apocalyptic number.

It is an amenable number.

211102021 is a deficient number, since it is larger than the sum of its proper divisors (20528819).

211102021 is a wasteful number, since it uses less digits than its factorization.

211102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306455.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 211102021 is about 14529.3503295915. The cubic root of 211102021 is about 595.4301162305.

Adding to 211102021 its reverse (120201112), we get a palindrome (331303133).

Subtracting from 211102021 its reverse (120201112), we obtain a palindrome (90900909).

The spelling of 211102021 in words is "two hundred eleven million, one hundred two thousand, twenty-one".