1643504099 has 2 divisors, whose sum is σ = 1643504100. Its totient is φ = 1643504098.

The previous prime is 1643504063. The next prime is 1643504117. The reversal of 1643504099 is 9904053461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1643504099 - 2²⁰ = 1642455523 is a prime.

It is a super-2 number, since 2×1643504099² = 5402211446859603602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1643504299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821752049 + 821752050.

It is an arithmetic number, because the mean of its divisors is an integer number (821752050).

Almost surely, 2^1643504099 is an apocalyptic number.

1643504099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643504099 is an equidigital number, since it uses as much as digits as its factorization.

1643504099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 1643504099 is about 40540.1541560957. The cubic root of 1643504099 is about 1180.1130072275.

The spelling of 1643504099 in words is "one billion, six hundred forty-three million, five hundred four thousand, ninety-nine".