1987155593 has 8 divisors (see below), whose sum is σ = 1995628488. Its totient is φ = 1978694784.

The previous prime is 1987155571. The next prime is 1987155601. The reversal of 1987155593 is 3955517891.

It can be written as a sum of positive squares in 4 ways, for example, as 511981129 + 1475174464 = 22627^2 + 38408^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1987155593 - 2¹⁰ = 1987154569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1987155563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 483455 + ... + 487547.

It is an arithmetic number, because the mean of its divisors is an integer number (249453561).

Almost surely, 2^1987155593 is an apocalyptic number.

It is an amenable number.

1987155593 is a deficient number, since it is larger than the sum of its proper divisors (8472895).

1987155593 is a wasteful number, since it uses less digits than its factorization.

1987155593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6043.

The product of its digits is 1701000, while the sum is 53.

The square root of 1987155593 is about 44577.5234058600. The cubic root of 1987155593 is about 1257.2180988510.

The spelling of 1987155593 in words is "one billion, nine hundred eighty-seven million, one hundred fifty-five thousand, five hundred ninety-three".