1405643856 has 80 divisors (see below), whose sum is σ = 3735635904. Its totient is φ = 455196672.

The previous prime is 1405643831. The next prime is 1405643867. The reversal of 1405643856 is 6583465041.

1405643856 = T₂₆₄ + T₂₆₅ + ... + T₂₀₃₆.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 404880 + ... + 408336.

Almost surely, 2^1405643856 is an apocalyptic number.

1405643856 is a gapful number since it is divisible by the number (16) 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 1405643856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1867817952).

1405643856 is an abundant number, since it is smaller than the sum of its proper divisors (2329992048).

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

1405643856 is a wasteful number, since it uses less digits than its factorization.

1405643856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3708 (or 3702 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 42.

The square root of 1405643856 is about 37491.9172089132. The cubic root of 1405643856 is about 1120.1901930406.

The spelling of 1405643856 in words is "one billion, four hundred five million, six hundred forty-three thousand, eight hundred fifty-six".