1955643840 has 168 divisors, whose sum is σ = 6743608560. Its totient is φ = 520187904.

The previous prime is 1955643829. The next prime is 1955643847. The reversal of 1955643840 is 483465591.

1955643840 is a `hidden beast` number, since 1 + 9 + 5 + 564 + 3 + 84 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955643847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1782172 + ... + 1783268.

Almost surely, 2^1955643840 is an apocalyptic number.

1955643840 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 1955643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3371804280).

1955643840 is an abundant number, since it is smaller than the sum of its proper divisors (4787964720).

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

1955643840 is a wasteful number, since it uses less digits than its factorization.

1955643840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1739 (or 1726 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The square root of 1955643840 is about 44222.6620636976. The cubic root of 1955643840 is about 1250.5371217005.

The spelling of 1955643840 in words is "one billion, nine hundred fifty-five million, six hundred forty-three thousand, eight hundred forty".