1641987 has 6 divisors (see below), whose sum is σ = 2371772. Its totient is φ = 1094652.

The previous prime is 1641971. The next prime is 1642021. The reversal of 1641987 is 7891461.

1641987 is a `hidden beast` number, since 1 + 641 + 9 + 8 + 7 = 666.

It is not a de Polignac number, because 1641987 - 2⁴ = 1641971 is a prime.

It is a super-2 number, since 2×1641987² = 5392242616338, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (1641907) 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, 91213 + ... + 91230.

2^1641987 is an apocalyptic number.

1641987 is a deficient number, since it is larger than the sum of its proper divisors (729785).

1641987 is a wasteful number, since it uses less digits than its factorization.

1641987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182449 (or 182446 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 1641987 is about 1281.4004058061. The cubic root of 1641987 is about 117.9749779368.

It can be divided in two parts, 1641 and 987, that added together give a triangular number (2628 = T₇₂).

The spelling of 1641987 in words is "one million, six hundred forty-one thousand, nine hundred eighty-seven".