1661597 has 8 divisors (see below), whose sum is σ = 2010816. Its totient is φ = 1340352.

The previous prime is 1661587. The next prime is 1661599. The reversal of 1661597 is 7951661.

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

It is a cyclic number.

It is not a de Polignac number, because 1661597 - 2¹⁰ = 1660573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661599) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6863 + ... + 7100.

It is an arithmetic number, because the mean of its divisors is an integer number (251352).

2^1661597 is an apocalyptic number.

1661597 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1661597 is a deficient number, since it is larger than the sum of its proper divisors (349219).

1661597 is a wasteful number, since it uses less digits than its factorization.

1661597 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13987.

The product of its digits is 11340, while the sum is 35.

The square root of 1661597 is about 1289.0294798801. The cubic root of 1661597 is about 118.4427729637.

Subtracting 1661597 from its reverse (7951661), we obtain a square (6290064 = 2508²).

The spelling of 1661597 in words is "one million, six hundred sixty-one thousand, five hundred ninety-seven".