1629661 has 4 divisors (see below), whose sum is σ = 1777824. Its totient is φ = 1481500.

The previous prime is 1629653. The next prime is 1629673. The reversal of 1629661 is 1669261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1629661 - 2³ = 1629653 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1629601) 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, 74065 + ... + 74086.

It is an arithmetic number, because the mean of its divisors is an integer number (444456).

2^1629661 is an apocalyptic number.

1629661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1629661 is a deficient number, since it is larger than the sum of its proper divisors (148163).

1629661 is a wasteful number, since it uses less digits than its factorization.

1629661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148162.

The product of its digits is 3888, while the sum is 31.

The square root of 1629661 is about 1276.5817639305. The cubic root of 1629661 is about 117.6790329416.

The spelling of 1629661 in words is "one million, six hundred twenty-nine thousand, six hundred sixty-one".