215041681 has 2 divisors, whose sum is σ = 215041682. Its totient is φ = 215041680.

The previous prime is 215041663. The next prime is 215041691. The reversal of 215041681 is 186140512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205062400 + 9979281 = 14320^2 + 3159^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215041681 is a prime.

It is a super-2 number, since 2×215041681² = 92485849134611522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (215041661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107520840 + 107520841.

It is an arithmetic number, because the mean of its divisors is an integer number (107520841).

Almost surely, 2^215041681 is an apocalyptic number.

It is an amenable number.

215041681 is a deficient number, since it is larger than the sum of its proper divisors (1).

215041681 is an equidigital number, since it uses as much as digits as its factorization.

215041681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 215041681 is about 14664.2995400394. The cubic root of 215041681 is about 599.1113520838. Note that the first 3 decimals are identical.

The spelling of 215041681 in words is "two hundred fifteen million, forty-one thousand, six hundred eighty-one".