211639949 has 2 divisors, whose sum is σ = 211639950. Its totient is φ = 211639948.

The previous prime is 211639943. The next prime is 211639969. The reversal of 211639949 is 949936112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199515625 + 12124324 = 14125^2 + 3482^2 .

It is a cyclic number.

It is not a de Polignac number, because 211639949 - 2⁴ = 211639933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211639943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105819974 + 105819975.

It is an arithmetic number, because the mean of its divisors is an integer number (105819975).

Almost surely, 2^211639949 is an apocalyptic number.

It is an amenable number.

211639949 is a deficient number, since it is larger than the sum of its proper divisors (1).

211639949 is an equidigital number, since it uses as much as digits as its factorization.

211639949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 44.

The square root of 211639949 is about 14547.8503222985. The cubic root of 211639949 is about 595.9354435505.

The spelling of 211639949 in words is "two hundred eleven million, six hundred thirty-nine thousand, nine hundred forty-nine".