1987438129 has 4 divisors (see below), whose sum is σ = 1989401076. Its totient is φ = 1985475184.

The previous prime is 1987438127. The next prime is 1987438147. The reversal of 1987438129 is 9218347891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 293951025 + 1693487104 = 17145^2 + 41152^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987438129 - 2¹ = 1987438127 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1987438127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979954 + ... + 981979.

It is an arithmetic number, because the mean of its divisors is an integer number (497350269).

Almost surely, 2^1987438129 is an apocalyptic number.

It is an amenable number.

1987438129 is a deficient number, since it is larger than the sum of its proper divisors (1962947).

1987438129 is a wasteful number, since it uses less digits than its factorization.

1987438129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1962946.

The product of its digits is 870912, while the sum is 52.

The square root of 1987438129 is about 44580.6923342381. The cubic root of 1987438129 is about 1257.2776802514.

The spelling of 1987438129 in words is "one billion, nine hundred eighty-seven million, four hundred thirty-eight thousand, one hundred twenty-nine".