1643495040 has 192 divisors, whose sum is σ = 6191359200. Its totient is φ = 398407680.

The previous prime is 1643495033. The next prime is 1643495053. The reversal of 1643495040 is 405943461.

1643495040 is a `hidden beast` number, since 1 + 643 + 4 + 9 + 5 + 0 + 4 + 0 = 666.

1643495040 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1643494986 and 1643495004.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50391 + ... + 76329.

Almost surely, 2^1643495040 is an apocalyptic number.

1643495040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643495040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3095679600).

1643495040 is an abundant number, since it is smaller than the sum of its proper divisors (4547864160).

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

1643495040 is a wasteful number, since it uses less digits than its factorization.

1643495040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25975 (or 25960 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1643495040 is about 40540.0424272102. The cubic root of 1643495040 is about 1180.1108389612.

The spelling of 1643495040 in words is "one billion, six hundred forty-three million, four hundred ninety-five thousand, forty".