1087921 has 4 divisors (see below), whose sum is σ = 1145200. Its totient is φ = 1030644.

The previous prime is 1087907. The next prime is 1087937. The reversal of 1087921 is 1297801.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1297801 = 137 ⋅9473.

It is a cyclic number.

It is not a de Polignac number, because 1087921 - 2⁹ = 1087409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1087921.

It is not an unprimeable number, because it can be changed into a prime (1087981) 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, 28611 + ... + 28648.

It is an arithmetic number, because the mean of its divisors is an integer number (286300).

2^1087921 is an apocalyptic number.

It is an amenable number.

1087921 is a deficient number, since it is larger than the sum of its proper divisors (57279).

1087921 is an equidigital number, since it uses as much as digits as its factorization.

1087921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57278.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 1087921 is about 1043.0345152487. The cubic root of 1087921 is about 102.8487742126.

The spelling of 1087921 in words is "one million, eighty-seven thousand, nine hundred twenty-one".