1919021 has 4 divisors (see below), whose sum is σ = 2066652. Its totient is φ = 1771392.

The previous prime is 1919009. The next prime is 1919039. The reversal of 1919021 is 1209191.

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

It can be written as a sum of positive squares in 2 ways, for example, as 940900 + 978121 = 970^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919021 - 2¹⁸ = 1656877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1919041) 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, 73796 + ... + 73821.

It is an arithmetic number, because the mean of its divisors is an integer number (516663).

2^1919021 is an apocalyptic number.

It is an amenable number.

1919021 is a deficient number, since it is larger than the sum of its proper divisors (147631).

1919021 is a wasteful number, since it uses less digits than its factorization.

1919021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147630.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 1919021 is about 1385.2873348154. The cubic root of 1919021 is about 124.2681717812.

The spelling of 1919021 in words is "one million, nine hundred nineteen thousand, twenty-one".