1641655 has 4 divisors (see below), whose sum is σ = 1969992. Its totient is φ = 1313320.

The previous prime is 1641641. The next prime is 1641659. The reversal of 1641655 is 5561461.

1641655 = 571² + 572² + ... + 575².

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1641655 - 2⁵ = 1641623 is a prime.

It is a super-2 number, since 2×1641655² = 5390062278050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641659) 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 3 ways as a sum of consecutive naturals, for example, 164161 + ... + 164170.

It is an arithmetic number, because the mean of its divisors is an integer number (492498).

2^1641655 is an apocalyptic number.

1641655 is a deficient number, since it is larger than the sum of its proper divisors (328337).

1641655 is an equidigital number, since it uses as much as digits as its factorization.

1641655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328336.

The product of its digits is 3600, while the sum is 28.

The square root of 1641655 is about 1281.2708534888. The cubic root of 1641655 is about 117.9670261213.

It can be divided in two parts, 16416 and 55, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 1641655 in words is "one million, six hundred forty-one thousand, six hundred fifty-five".