211732921 has 2 divisors, whose sum is σ = 211732922. Its totient is φ = 211732920.

The previous prime is 211732879. The next prime is 211732951. The reversal of 211732921 is 129237112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145082025 + 66650896 = 12045^2 + 8164^2 .

It is a cyclic number.

It is not a de Polignac number, because 211732921 - 2²³ = 203344313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211732921.

It is not a weakly prime, because it can be changed into another prime (211732951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105866460 + 105866461.

It is an arithmetic number, because the mean of its divisors is an integer number (105866461).

Almost surely, 2^211732921 is an apocalyptic number.

It is an amenable number.

211732921 is a deficient number, since it is larger than the sum of its proper divisors (1).

211732921 is an equidigital number, since it uses as much as digits as its factorization.

211732921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1512, while the sum is 28.

The square root of 211732921 is about 14551.0453576367. The cubic root of 211732921 is about 596.0226942472.

The spelling of 211732921 in words is "two hundred eleven million, seven hundred thirty-two thousand, nine hundred twenty-one".