216871937 has 2 divisors, whose sum is σ = 216871938. Its totient is φ = 216871936.

The previous prime is 216871933. The next prime is 216871951. The reversal of 216871937 is 739178612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167857936 + 49014001 = 12956^2 + 7001^2 .

It is a cyclic number.

It is not a de Polignac number, because 216871937 - 2² = 216871933 is a prime.

It is not a weakly prime, because it can be changed into another prime (216871933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108435968 + 108435969.

It is an arithmetic number, because the mean of its divisors is an integer number (108435969).

Almost surely, 2^216871937 is an apocalyptic number.

It is an amenable number.

216871937 is a deficient number, since it is larger than the sum of its proper divisors (1).

216871937 is an equidigital number, since it uses as much as digits as its factorization.

216871937 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 44.

The square root of 216871937 is about 14726.5724797048. The cubic root of 216871937 is about 600.8062651496.

The spelling of 216871937 in words is "two hundred sixteen million, eight hundred seventy-one thousand, nine hundred thirty-seven".