1621161 has 16 divisors (see below), whose sum is σ = 2430400. Its totient is φ = 1067904.

The previous prime is 1621153. The next prime is 1621163. The reversal of 1621161 is 1611261.

It is not a de Polignac number, because 1621161 - 2³ = 1621153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2310 + ... + 2928.

It is an arithmetic number, because the mean of its divisors is an integer number (151900).

2^1621161 is an apocalyptic number.

It is an amenable number.

1621161 is a deficient number, since it is larger than the sum of its proper divisors (809239).

1621161 is an equidigital number, since it uses as much as digits as its factorization.

1621161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725 (or 719 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 1621161 is about 1273.2482083239. The cubic root of 1621161 is about 117.4740790868.

The spelling of 1621161 in words is "one million, six hundred twenty-one thousand, one hundred sixty-one".