211621013 has 4 divisors (see below), whose sum is σ = 214299840. Its totient is φ = 208942188.

The previous prime is 211621001. The next prime is 211621027. The reversal of 211621013 is 310126112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211621013 - 2⁶ = 211620949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211620982 and 211621000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211621043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1339295 + ... + 1339452.

It is an arithmetic number, because the mean of its divisors is an integer number (53574960).

Almost surely, 2^211621013 is an apocalyptic number.

It is an amenable number.

211621013 is a deficient number, since it is larger than the sum of its proper divisors (2678827).

211621013 is an equidigital number, since it uses as much as digits as its factorization.

211621013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2678826.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 211621013 is about 14547.1994899362. The cubic root of 211621013 is about 595.9176697005.

Adding to 211621013 its reverse (310126112), we get a palindrome (521747125).

The spelling of 211621013 in words is "two hundred eleven million, six hundred twenty-one thousand, thirteen".