155615987 has 4 divisors (see below), whose sum is σ = 155736720. Its totient is φ = 155495256.

The previous prime is 155615923. The next prime is 155616031. The reversal of 155615987 is 789516551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789516551 = 2887 ⋅273473.

It is a cyclic number.

It is not a de Polignac number, because 155615987 - 2⁶ = 155615923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155615917) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 58412 + ... + 61017.

It is an arithmetic number, because the mean of its divisors is an integer number (38934180).

Almost surely, 2^155615987 is an apocalyptic number.

155615987 is a deficient number, since it is larger than the sum of its proper divisors (120733).

155615987 is a wasteful number, since it uses less digits than its factorization.

155615987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120732.

The product of its digits is 378000, while the sum is 47.

The square root of 155615987 is about 12474.6137014338. The cubic root of 155615987 is about 537.8791838179.

The spelling of 155615987 in words is "one hundred fifty-five million, six hundred fifteen thousand, nine hundred eighty-seven".