1938994987 has 4 divisors (see below), whose sum is σ = 1943623080. Its totient is φ = 1934366896.

The previous prime is 1938994969. The next prime is 1938994997. The reversal of 1938994987 is 7894998391.

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

It is a cyclic number.

It is not a de Polignac number, because 1938994987 - 2¹⁵ = 1938962219 is a prime.

It is a super-2 number, since 2×1938994987² = 7519403119222260338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1938994927) 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, 2313418 + ... + 2314255.

It is an arithmetic number, because the mean of its divisors is an integer number (485905770).

Almost surely, 2^1938994987 is an apocalyptic number.

1938994987 is a deficient number, since it is larger than the sum of its proper divisors (4628093).

1938994987 is an equidigital number, since it uses as much as digits as its factorization.

1938994987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4628092.

The product of its digits is 35271936, while the sum is 67.

The square root of 1938994987 is about 44034.0207907477. The cubic root of 1938994987 is about 1246.9782985689.

The spelling of 1938994987 in words is "one billion, nine hundred thirty-eight million, nine hundred ninety-four thousand, nine hundred eighty-seven".