1661522 has 8 divisors (see below), whose sum is σ = 2559756. Its totient is φ = 808272.

The previous prime is 1661519. The next prime is 1661549. The reversal of 1661522 is 2251661.

It is a Cunningham number, because it is equal to 1289²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 1661521 + 1 = 1289^2 + 1^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11153 + ... + 11300.

2^1661522 is an apocalyptic number.

1661522 is a deficient number, since it is larger than the sum of its proper divisors (898234).

1661522 is a wasteful number, since it uses less digits than its factorization.

1661522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22492.

The product of its digits is 720, while the sum is 23.

The square root of 1661522 is about 1289.0003878975. Note that the first 3 decimals coincide. The cubic root of 1661522 is about 118.4409908746.

The spelling of 1661522 in words is "one million, six hundred sixty-one thousand, five hundred twenty-two".