1921601 has 6 divisors (see below), whose sum is σ = 2112306. Its totient is φ = 1746800.

The previous prime is 1921573. The next prime is 1921631. The reversal of 1921601 is 1061291.

It can be written as a sum of positive squares in only one way, i.e., 1890625 + 30976 = 1375^2 + 176^2 .

It is not a de Polignac number, because 1921601 - 2⁶ = 1921537 is a prime.

It is a Duffinian number.

It is a plaindrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (1921631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7820 + ... + 8061.

It is an arithmetic number, because the mean of its divisors is an integer number (352051).

2^1921601 is an apocalyptic number.

1921601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1921601 is a deficient number, since it is larger than the sum of its proper divisors (190705).

1921601 is a wasteful number, since it uses less digits than its factorization.

1921601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15903 (or 15892 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 1921601 is about 1386.2182367867. The cubic root of 1921601 is about 124.3238370240.

Adding to 1921601 its reverse (1061291), we get a palindrome (2982892).

The spelling of 1921601 in words is "one million, nine hundred twenty-one thousand, six hundred one".