1611921 has 4 divisors (see below), whose sum is σ = 2149232. Its totient is φ = 1074612.

The previous prime is 1611917. The next prime is 1611947. The reversal of 1611921 is 1291161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1611921 - 2² = 1611917 is a prime.

It is a D-number.

It is a Duffinian number.

1611921 is a lucky number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1611901) 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, 268651 + ... + 268656.

It is an arithmetic number, because the mean of its divisors is an integer number (537308).

2^1611921 is an apocalyptic number.

It is an amenable number.

1611921 is a deficient number, since it is larger than the sum of its proper divisors (537311).

1611921 is an equidigital number, since it uses as much as digits as its factorization.

1611921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537310.

The product of its digits is 108, while the sum is 21.

The square root of 1611921 is about 1269.6145084237. The cubic root of 1611921 is about 117.2504678841.

The spelling of 1611921 in words is "one million, six hundred eleven thousand, nine hundred twenty-one".