1921555 has 8 divisors (see below), whose sum is σ = 2317392. Its totient is φ = 1529568.

The previous prime is 1921553. The next prime is 1921559. The reversal of 1921555 is 5551291.

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 1921555 - 2¹ = 1921553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289 + ... + 1981.

It is an arithmetic number, because the mean of its divisors is an integer number (289674).

2^1921555 is an apocalyptic number.

1921555 is a deficient number, since it is larger than the sum of its proper divisors (395837).

1921555 is a wasteful number, since it uses less digits than its factorization.

1921555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1925.

The product of its digits is 2250, while the sum is 28.

The square root of 1921555 is about 1386.2016447833. The cubic root of 1921555 is about 124.3228449793.

The spelling of 1921555 in words is "one million, nine hundred twenty-one thousand, five hundred fifty-five".