1990495840 has 48 divisors (see below), whose sum is σ = 4720941792. Its totient is φ = 793083904.

The previous prime is 1990495799. The next prime is 1990495861. The reversal of 1990495840 is 485940991.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16917 + ... + 65323.

It is an arithmetic number, because the mean of its divisors is an integer number (98352954).

Almost surely, 2^1990495840 is an apocalyptic number.

1990495840 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 1990495840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2360470896).

1990495840 is an abundant number, since it is smaller than the sum of its proper divisors (2730445952).

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

1990495840 is a wasteful number, since it uses less digits than its factorization.

1990495840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48679 (or 48671 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 49.

The square root of 1990495840 is about 44614.9732713133. The cubic root of 1990495840 is about 1257.9221316625.

The spelling of 1990495840 in words is "one billion, nine hundred ninety million, four hundred ninety-five thousand, eight hundred forty".