1991562240 has 352 divisors, whose sum is σ = 7003687680. Its totient is φ = 480772096.

The previous prime is 1991562229. The next prime is 1991562253. The reversal of 1991562240 is 422651991.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7572349 + ... + 7572611.

It is an arithmetic number, because the mean of its divisors is an integer number (19896840).

Almost surely, 2^1991562240 is an apocalyptic number.

1991562240 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 1991562240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3501843840).

1991562240 is an abundant number, since it is smaller than the sum of its proper divisors (5012125440).

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

1991562240 is a wasteful number, since it uses less digits than its factorization.

1991562240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337 (or 319 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 1991562240 is about 44626.9228157174. The cubic root of 1991562240 is about 1258.1467337687.

The spelling of 1991562240 in words is "one billion, nine hundred ninety-one million, five hundred sixty-two thousand, two hundred forty".