1987749394 has 8 divisors (see below), whose sum is σ = 2982576240. Its totient is φ = 993557316.

The previous prime is 1987749383. The next prime is 1987749403. The reversal of 1987749394 is 4939477891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1987749394² = 7902295306694734472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150784 + ... + 163435.

It is an arithmetic number, because the mean of its divisors is an integer number (372822030).

Almost surely, 2^1987749394 is an apocalyptic number.

1987749394 is a deficient number, since it is larger than the sum of its proper divisors (994826846).

1987749394 is a wasteful number, since it uses less digits than its factorization.

1987749394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317384.

The product of its digits is 13716864, while the sum is 61.

The square root of 1987749394 is about 44584.1832267902. The cubic root of 1987749394 is about 1257.3433135077.

The spelling of 1987749394 in words is "one billion, nine hundred eighty-seven million, seven hundred forty-nine thousand, three hundred ninety-four".