1906921 has 8 divisors (see below), whose sum is σ = 1985984. Its totient is φ = 1829520.

The previous prime is 1906909. The next prime is 1906963. The reversal of 1906921 is 1296091.

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

It is a cyclic number.

It is not a de Polignac number, because 1906921 - 2⁵ = 1906889 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 1906921.

It is not an unprimeable number, because it can be changed into a prime (1906321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2260 + ... + 2986.

It is an arithmetic number, because the mean of its divisors is an integer number (248248).

2^1906921 is an apocalyptic number.

It is an amenable number.

1906921 is a deficient number, since it is larger than the sum of its proper divisors (79063).

1906921 is an equidigital number, since it uses as much as digits as its factorization.

1906921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 831.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 1906921 is about 1380.9131037107. The cubic root of 1906921 is about 124.0064382713.

The spelling of 1906921 in words is "one million, nine hundred six thousand, nine hundred twenty-one".