1643000401 has 4 divisors (see below), whose sum is σ = 1877714752. Its totient is φ = 1408286052.

The previous prime is 1643000399. The next prime is 1643000419. The reversal of 1643000401 is 1040003461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1643000401 - 2¹ = 1643000399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643000461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117357165 + ... + 117357178.

It is an arithmetic number, because the mean of its divisors is an integer number (469428688).

Almost surely, 2^1643000401 is an apocalyptic number.

It is an amenable number.

1643000401 is a deficient number, since it is larger than the sum of its proper divisors (234714351).

1643000401 is an equidigital number, since it uses as much as digits as its factorization.

1643000401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234714350.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 1643000401 is about 40533.9413454946. The cubic root of 1643000401 is about 1179.9924353149.

Adding to 1643000401 its reverse (1040003461), we get a palindrome (2683003862).

The spelling of 1643000401 in words is "one billion, six hundred forty-three million, four hundred one", and thus it is an aban number.