1587997440 has 144 divisors (see below), whose sum is σ = 5635308000. Its totient is φ = 423456768.

The previous prime is 1587997423. The next prime is 1587997451. The reversal of 1587997440 is 447997851.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11586 + ... + 57534.

Almost surely, 2^1587997440 is an apocalyptic number.

1587997440 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 1587997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2817654000).

1587997440 is an abundant number, since it is smaller than the sum of its proper divisors (4047310560).

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

1587997440 is an equidigital number, since it uses as much as digits as its factorization.

1587997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45979 (or 45959 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The square root of 1587997440 is about 39849.6855696504. The cubic root of 1587997440 is about 1166.6751099616.

The spelling of 1587997440 in words is "one billion, five hundred eighty-seven million, nine hundred ninety-seven thousand, four hundred forty".