1629561 has 4 divisors (see below), whose sum is σ = 2172752. Its totient is φ = 1086372.

The previous prime is 1629559. The next prime is 1629581. The reversal of 1629561 is 1659261.

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 not a de Polignac number, because 1629561 - 2¹ = 1629559 is a prime.

It is a D-number.

It is a Duffinian number.

1629561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1629541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271591 + ... + 271596.

It is an arithmetic number, because the mean of its divisors is an integer number (543188).

2^1629561 is an apocalyptic number.

It is an amenable number.

1629561 is a deficient number, since it is larger than the sum of its proper divisors (543191).

1629561 is an equidigital number, since it uses as much as digits as its factorization.

1629561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 543190.

The product of its digits is 3240, while the sum is 30.

The square root of 1629561 is about 1276.5425962341. The cubic root of 1629561 is about 117.6766258676.

The spelling of 1629561 in words is "one million, six hundred twenty-nine thousand, five hundred sixty-one".