1987733057 has 4 divisors (see below), whose sum is σ = 1991638740. Its totient is φ = 1983827376.

The previous prime is 1987733017. The next prime is 1987733063. The reversal of 1987733057 is 7503377891.

It is a Cunningham number, because it is equal to 44584²+1.

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 1616361616 + 371371441 = 40204^2 + 19271^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987733057 - 2⁸ = 1987732801 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1987732996 and 1987733014.

It is not an unprimeable number, because it can be changed into a prime (1987733017) 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, 1952078 + ... + 1953095.

It is an arithmetic number, because the mean of its divisors is an integer number (497909685).

Almost surely, 2^1987733057 is an apocalyptic number.

It is an amenable number.

1987733057 is a deficient number, since it is larger than the sum of its proper divisors (3905683).

1987733057 is an equidigital number, since it uses as much as digits as its factorization.

1987733057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3905682.

The product of its (nonzero) digits is 1111320, while the sum is 50.

The square root of 1987733057 is about 44584.0000112148. Note that the first 4 decimals coincide. The cubic root of 1987733057 is about 1257.3398688626.

The spelling of 1987733057 in words is "one billion, nine hundred eighty-seven million, seven hundred thirty-three thousand, fifty-seven".