1645722056 has 64 divisors (see below), whose sum is σ = 3412886400. Its totient is φ = 737766400.

The previous prime is 1645722037. The next prime is 1645722103. The reversal of 1645722056 is 6502275461.

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, 3569666 + ... + 3570126.

It is an arithmetic number, because the mean of its divisors is an integer number (53326350).

Almost surely, 2^1645722056 is an apocalyptic number.

It is a pronic number, being equal to 40567×40568.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645722056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1706443200).

1645722056 is an abundant number, since it is smaller than the sum of its proper divisors (1767164344).

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

1645722056 is a wasteful number, since it uses less digits than its factorization.

1645722056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950 (or 946 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 1645722056 is about 40567.4999969187. The cubic root of 1645722056 is about 1180.6436343088.

The spelling of 1645722056 in words is "one billion, six hundred forty-five million, seven hundred twenty-two thousand, fifty-six".