1770661 has 4 divisors (see below), whose sum is σ = 1773324. Its totient is φ = 1768000.

The previous prime is 1770617. The next prime is 1770679. The reversal of 1770661 is 1660771.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 93636 + 1677025 = 306^2 + 1295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1770661 - 2¹⁹ = 1246373 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 (1770061) 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, 621 + ... + 1981.

It is an arithmetic number, because the mean of its divisors is an integer number (443331).

2^1770661 is an apocalyptic number.

It is an amenable number.

1770661 is a deficient number, since it is larger than the sum of its proper divisors (2663).

1770661 is a wasteful number, since it uses less digits than its factorization.

1770661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2662.

The product of its (nonzero) digits is 1764, while the sum is 28.

The square root of 1770661 is about 1330.6618653888. The cubic root of 1770661 is about 120.9795061255.

The spelling of 1770661 in words is "one million, seven hundred seventy thousand, six hundred sixty-one".