211421261 has 4 divisors (see below), whose sum is σ = 211462272. Its totient is φ = 211380252.

The previous prime is 211421257. The next prime is 211421317. The reversal of 211421261 is 162124112.

It is a happy number.

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 211421261 - 2² = 211421257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211421251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11435 + ... + 23528.

It is an arithmetic number, because the mean of its divisors is an integer number (52865568).

Almost surely, 2^211421261 is an apocalyptic number.

It is an amenable number.

211421261 is a deficient number, since it is larger than the sum of its proper divisors (41011).

211421261 is an equidigital number, since it uses as much as digits as its factorization.

211421261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41010.

The product of its digits is 192, while the sum is 20.

The square root of 211421261 is about 14540.3322176627. The cubic root of 211421261 is about 595.7301123663.

Adding to 211421261 its reverse (162124112), we get a palindrome (373545373).

The spelling of 211421261 in words is "two hundred eleven million, four hundred twenty-one thousand, two hundred sixty-one".