1641649 has 4 divisors (see below), whose sum is σ = 1656820. Its totient is φ = 1626480.

The previous prime is 1641641. The next prime is 1641659. The reversal of 1641649 is 9461461.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1210000 + 431649 = 1100^2 + 657^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641649 - 2³ = 1641641 is a prime.

It is a super-2 number, since 2×1641649² = 5390022878402, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1641649.

It is not an unprimeable number, because it can be changed into a prime (1641641) 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, 7422 + ... + 7639.

It is an arithmetic number, because the mean of its divisors is an integer number (414205).

2^1641649 is an apocalyptic number.

It is an amenable number.

1641649 is a deficient number, since it is larger than the sum of its proper divisors (15171).

1641649 is a wasteful number, since it uses less digits than its factorization.

1641649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15170.

The product of its digits is 5184, while the sum is 31.

The square root of 1641649 is about 1281.2685120614. The cubic root of 1641649 is about 117.9668824040.

The spelling of 1641649 in words is "one million, six hundred forty-one thousand, six hundred forty-nine".