1995861840 has 320 divisors, whose sum is σ = 7687127040. Its totient is φ = 418037760.

The previous prime is 1995861827. The next prime is 1995861877. The reversal of 1995861840 is 481685991.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 988512 + ... + 990528.

It is an arithmetic number, because the mean of its divisors is an integer number (24022272).

Almost surely, 2^1995861840 is an apocalyptic number.

1995861840 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 1995861840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3843563520).

1995861840 is an abundant number, since it is smaller than the sum of its proper divisors (5691265200).

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

1995861840 is a wasteful number, since it uses less digits than its factorization.

1995861840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2090 (or 2084 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 51.

The square root of 1995861840 is about 44675.0695578641. The cubic root of 1995861840 is about 1259.0514907410.

The spelling of 1995861840 in words is "one billion, nine hundred ninety-five million, eight hundred sixty-one thousand, eight hundred forty".