1945921 has 4 divisors (see below), whose sum is σ = 1952452. Its totient is φ = 1939392.

The previous prime is 1945919. The next prime is 1945943. The reversal of 1945921 is 1295491.

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 541696 + 1404225 = 736^2 + 1185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1945921 - 2¹ = 1945919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1945981) 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, 2796 + ... + 3421.

It is an arithmetic number, because the mean of its divisors is an integer number (488113).

2^1945921 is an apocalyptic number.

It is an amenable number.

1945921 is a deficient number, since it is larger than the sum of its proper divisors (6531).

1945921 is an equidigital number, since it uses as much as digits as its factorization.

1945921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6530.

The product of its digits is 3240, while the sum is 31.

The square root of 1945921 is about 1394.9627235163. The cubic root of 1945921 is about 124.8461253251.

The spelling of 1945921 in words is "one million, nine hundred forty-five thousand, nine hundred twenty-one".