1643255405 has 16 divisors (see below), whose sum is σ = 2166882624. Its totient is φ = 1186366080.

The previous prime is 1643255387. The next prime is 1643255417. The reversal of 1643255405 is 5045523461.

It is not a de Polignac number, because 1643255405 - 2¹⁴ = 1643239021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101507 + ... + 116576.

It is an arithmetic number, because the mean of its divisors is an integer number (135430164).

Almost surely, 2^1643255405 is an apocalyptic number.

It is an amenable number.

1643255405 is a deficient number, since it is larger than the sum of its proper divisors (523627219).

1643255405 is a wasteful number, since it uses less digits than its factorization.

1643255405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218236.

The product of its (nonzero) digits is 72000, while the sum is 35.

The square root of 1643255405 is about 40537.0867848197. The cubic root of 1643255405 is about 1180.0534795737.

Adding to 1643255405 its reverse (5045523461), we get a palindrome (6688778866).

The spelling of 1643255405 in words is "one billion, six hundred forty-three million, two hundred fifty-five thousand, four hundred five".