1587145921 has 3 divisors (see below), whose sum is σ = 1587185761. Its totient is φ = 1587106082.

The previous prime is 1587145909. The next prime is 1587145927. The reversal of 1587145921 is 1295417851.

The square root of 1587145921 is 39839.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-1587145921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1587145927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 19920 + ... + 59758.

Almost surely, 2^1587145921 is an apocalyptic number.

1587145921 is the 39839-th square number.

1587145921 is the 19920-th centered octagonal number.

It is an amenable number.

1587145921 is a deficient number, since it is larger than the sum of its proper divisors (39840).

1587145921 is an frugal number, since it uses more digits than its factorization.

1587145921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79678 (or 39839 counting only the distinct ones).

The product of its digits is 100800, while the sum is 43.

The cubic root of 1587145921 is about 1166.4665404303.

The spelling of 1587145921 in words is "one billion, five hundred eighty-seven million, one hundred forty-five thousand, nine hundred twenty-one".