211542137 has 2 divisors, whose sum is σ = 211542138. Its totient is φ = 211542136.

The previous prime is 211542113. The next prime is 211542167. The reversal of 211542137 is 731245112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201327721 + 10214416 = 14189^2 + 3196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211542137 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (211542167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105771068 + 105771069.

It is an arithmetic number, because the mean of its divisors is an integer number (105771069).

Almost surely, 2^211542137 is an apocalyptic number.

It is an amenable number.

211542137 is a deficient number, since it is larger than the sum of its proper divisors (1).

211542137 is an equidigital number, since it uses as much as digits as its factorization.

211542137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 26.

The square root of 211542137 is about 14544.4882000021. The cubic root of 211542137 is about 595.8436231106.

Adding to 211542137 its reverse (731245112), we get a palindrome (942787249).

The spelling of 211542137 in words is "two hundred eleven million, five hundred forty-two thousand, one hundred thirty-seven".