1643950490 has 288 divisors, whose sum is σ = 4233358080. Its totient is φ = 454035456.

The previous prime is 1643950459. The next prime is 1643950493. The reversal of 1643950490 is 940593461.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643950493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 34977647 + ... + 34977693.

It is an arithmetic number, because the mean of its divisors is an integer number (14699160).

Almost surely, 2^1643950490 is an apocalyptic number.

1643950490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1643950490 is an abundant number, since it is smaller than the sum of its proper divisors (2589407590).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643950490 is a wasteful number, since it uses less digits than its factorization.

1643950490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134 (or 110 counting only the distinct ones).

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

The square root of 1643950490 is about 40545.6593237797. The cubic root of 1643950490 is about 1180.2198407788.

The spelling of 1643950490 in words is "one billion, six hundred forty-three million, nine hundred fifty thousand, four hundred ninety".