1643131741 has 2 divisors, whose sum is σ = 1643131742. Its totient is φ = 1643131740.

The previous prime is 1643131739. The next prime is 1643131747. The reversal of 1643131741 is 1471313461.

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., 1587703716 + 55428025 = 39846^2 + 7445^2 .

It is an emirp because it is prime and its reverse (1471313461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1643131741 - 2¹ = 1643131739 is a prime.

Together with 1643131739, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1643131747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821565870 + 821565871.

It is an arithmetic number, because the mean of its divisors is an integer number (821565871).

Almost surely, 2^1643131741 is an apocalyptic number.

It is an amenable number.

1643131741 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643131741 is an equidigital number, since it uses as much as digits as its factorization.

1643131741 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 1643131741 is about 40535.5614368421. The cubic root of 1643131741 is about 1180.0238769946.

The spelling of 1643131741 in words is "one billion, six hundred forty-three million, one hundred thirty-one thousand, seven hundred forty-one".