1915987 has 6 divisors (see below), whose sum is σ = 1946868. Its totient is φ = 1885572.

The previous prime is 1915981. The next prime is 1915993. The reversal of 1915987 is 7895191.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1915981) and next prime (1915993).

It is not a de Polignac number, because 1915987 - 2¹¹ = 1913939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1915981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6088 + ... + 6394.

It is an arithmetic number, because the mean of its divisors is an integer number (324478).

2^1915987 is an apocalyptic number.

1915987 is a deficient number, since it is larger than the sum of its proper divisors (30881).

1915987 is an frugal number, since it uses more digits than its factorization.

1915987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465 (or 386 counting only the distinct ones).

The product of its digits is 22680, while the sum is 40.

The square root of 1915987 is about 1384.1918219669. The cubic root of 1915987 is about 124.2026473108.

The spelling of 1915987 in words is "one million, nine hundred fifteen thousand, nine hundred eighty-seven".