211021649 has 4 divisors (see below), whose sum is σ = 211648164. Its totient is φ = 210395136.

The previous prime is 211021637. The next prime is 211021651. The reversal of 211021649 is 946120112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36966400 + 174055249 = 6080^2 + 13193^2 .

It is a cyclic number.

It is not a de Polignac number, because 211021649 - 2¹⁶ = 210956113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211021949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312752 + ... + 313425.

It is an arithmetic number, because the mean of its divisors is an integer number (52912041).

Almost surely, 2^211021649 is an apocalyptic number.

It is an amenable number.

211021649 is a deficient number, since it is larger than the sum of its proper divisors (626515).

211021649 is an equidigital number, since it uses as much as digits as its factorization.

211021649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626514.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 211021649 is about 14526.5842165321. The cubic root of 211021649 is about 595.3545414228.

The spelling of 211021649 in words is "two hundred eleven million, twenty-one thousand, six hundred forty-nine".