1655921 has 2 divisors, whose sum is σ = 1655922. Its totient is φ = 1655920.

The previous prime is 1655909. The next prime is 1655939. The reversal of 1655921 is 1295561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1600225 + 55696 = 1265^2 + 236^2 .

It is an emirp because it is prime and its reverse (1295561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1655921 - 2¹⁰ = 1654897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1655981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 827960 + 827961.

It is an arithmetic number, because the mean of its divisors is an integer number (827961).

2^1655921 is an apocalyptic number.

It is an amenable number.

1655921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1655921 is an equidigital number, since it uses as much as digits as its factorization.

1655921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 29.

The square root of 1655921 is about 1286.8259400556. The cubic root of 1655921 is about 118.3077526314.

The spelling of 1655921 in words is "one million, six hundred fifty-five thousand, nine hundred twenty-one".