1643629 has 4 divisors (see below), whose sum is σ = 1770076. Its totient is φ = 1517184.

The previous prime is 1643623. The next prime is 1643639. The reversal of 1643629 is 9263461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9263461 = 79 ⋅117259.

It can be written as a sum of positive squares in 2 ways, for example, as 806404 + 837225 = 898^2 + 915^2 .

It is a cyclic number.

It is not a de Polignac number, because 1643629 - 2⁵ = 1643597 is a prime.

It is a d-powerful number, because it can be written as 1 + 6² + 4⁷ + 3¹³ + 6² + 2¹⁵ + 9² .

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 1643629.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643623) 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, 63204 + ... + 63229.

It is an arithmetic number, because the mean of its divisors is an integer number (442519).

2^1643629 is an apocalyptic number.

It is an amenable number.

1643629 is a deficient number, since it is larger than the sum of its proper divisors (126447).

1643629 is a wasteful number, since it uses less digits than its factorization.

1643629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126446.

The product of its digits is 7776, while the sum is 31.

The square root of 1643629 is about 1282.0409509840. The cubic root of 1643629 is about 118.0142901395.

The spelling of 1643629 in words is "one million, six hundred forty-three thousand, six hundred twenty-nine".