1661288 has 8 divisors (see below), whose sum is σ = 3114930. Its totient is φ = 830640.

The previous prime is 1661281. The next prime is 1661293. The reversal of 1661288 is 8821661.

It can be written as a sum of positive squares in only one way, i.e., 1592644 + 68644 = 1262^2 + 262^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (1661281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103823 + ... + 103838.

2^1661288 is an apocalyptic number.

It is an amenable number.

1661288 is a deficient number, since it is larger than the sum of its proper divisors (1453642).

1661288 is a wasteful number, since it uses less digits than its factorization.

1661288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207667 (or 207663 counting only the distinct ones).

The product of its digits is 4608, while the sum is 32.

The square root of 1661288 is about 1288.9096166916. The cubic root of 1661288 is about 118.4354304120.

The spelling of 1661288 in words is "one million, six hundred sixty-one thousand, two hundred eighty-eight".