1921915 has 4 divisors (see below), whose sum is σ = 2306304. Its totient is φ = 1537528.

The previous prime is 1921889. The next prime is 1921919. The reversal of 1921915 is 5191291.

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

It is a cyclic number.

It is not a de Polignac number, because 1921915 - 2⁵ = 1921883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921919) 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, 192187 + ... + 192196.

It is an arithmetic number, because the mean of its divisors is an integer number (576576).

2^1921915 is an apocalyptic number.

1921915 is a deficient number, since it is larger than the sum of its proper divisors (384389).

1921915 is an equidigital number, since it uses as much as digits as its factorization.

1921915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384388.

The product of its digits is 810, while the sum is 28.

The square root of 1921915 is about 1386.3314899403. The cubic root of 1921915 is about 124.3306083844.

The spelling of 1921915 in words is "one million, nine hundred twenty-one thousand, nine hundred fifteen".