3945555640 has 128 divisors (see below), whose sum is σ = 9786873600. Its totient is φ = 1422673920.

The previous prime is 3945555587. The next prime is 3945555661. The reversal of 3945555640 is 465555493.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 5487201 + ... + 5487919.

It is an arithmetic number, because the mean of its divisors is an integer number (76459950).

Almost surely, 2^3945555640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3945555640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4893436800).

3945555640 is an abundant number, since it is smaller than the sum of its proper divisors (5841317960).

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

3945555640 is a wasteful number, since it uses less digits than its factorization.

3945555640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 977 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 1620000, while the sum is 46.

The square root of 3945555640 is about 62813.6580689264. The cubic root of 3945555640 is about 1580.1660403403.

The spelling of 3945555640 in words is "three billion, nine hundred forty-five million, five hundred fifty-five thousand, six hundred forty".