1999782137 has 4 divisors (see below), whose sum is σ = 2006090916. Its totient is φ = 1993473360.

The previous prime is 1999782133. The next prime is 1999782139. The reversal of 1999782137 is 7312879991.

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 230402041 + 1769380096 = 15179^2 + 42064^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999782137 - 2² = 1999782133 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1999782133) 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, 3153914 + ... + 3154547.

It is an arithmetic number, because the mean of its divisors is an integer number (501522729).

Almost surely, 2^1999782137 is an apocalyptic number.

It is an amenable number.

1999782137 is a deficient number, since it is larger than the sum of its proper divisors (6308779).

1999782137 is an equidigital number, since it uses as much as digits as its factorization.

1999782137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6308778.

The product of its digits is 1714608, while the sum is 56.

The square root of 1999782137 is about 44718.9237012699. The cubic root of 1999782137 is about 1259.8752998703.

The spelling of 1999782137 in words is "one billion, nine hundred ninety-nine million, seven hundred eighty-two thousand, one hundred thirty-seven".