1921387 has 4 divisors (see below), whose sum is σ = 2069200. Its totient is φ = 1773576.

The previous prime is 1921363. The next prime is 1921393. The reversal of 1921387 is 7831291.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921387 is a prime.

It is a Duffinian number.

1921387 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1921307) 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, 73887 + ... + 73912.

It is an arithmetic number, because the mean of its divisors is an integer number (517300).

2^1921387 is an apocalyptic number.

1921387 is a deficient number, since it is larger than the sum of its proper divisors (147813).

1921387 is a wasteful number, since it uses less digits than its factorization.

1921387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147812.

The product of its digits is 3024, while the sum is 31.

The square root of 1921387 is about 1386.1410462143. The cubic root of 1921387 is about 124.3192217251.

The spelling of 1921387 in words is "one million, nine hundred twenty-one thousand, three hundred eighty-seven".