1643136227 has 2 divisors, whose sum is σ = 1643136228. Its totient is φ = 1643136226.

The previous prime is 1643136223. The next prime is 1643136239. The reversal of 1643136227 is 7226313461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1643136227 - 2² = 1643136223 is a prime.

It is not a weakly prime, because it can be changed into another prime (1643136223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821568113 + 821568114.

It is an arithmetic number, because the mean of its divisors is an integer number (821568114).

Almost surely, 2^1643136227 is an apocalyptic number.

1643136227 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643136227 is an equidigital number, since it uses as much as digits as its factorization.

1643136227 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 35.

The square root of 1643136227 is about 40535.6167709337. The cubic root of 1643136227 is about 1180.0249508753.

Adding to 1643136227 its reverse (7226313461), we get a palindrome (8869449688).

The spelling of 1643136227 in words is "one billion, six hundred forty-three million, one hundred thirty-six thousand, two hundred twenty-seven".