1661801 has 8 divisors (see below), whose sum is σ = 1787040. Its totient is φ = 1539648.

The previous prime is 1661789. The next prime is 1661813. The reversal of 1661801 is 1081661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1661789) and next prime (1661813).

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 1661801 - 2¹⁴ = 1645417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661831) 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, 410 + ... + 1868.

It is an arithmetic number, because the mean of its divisors is an integer number (223380).

2^1661801 is an apocalyptic number.

It is an amenable number.

1661801 is a deficient number, since it is larger than the sum of its proper divisors (125239).

1661801 is a wasteful number, since it uses less digits than its factorization.

1661801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1661801 is about 1289.1086067512. The cubic root of 1661801 is about 118.4476199747.

The spelling of 1661801 in words is "one million, six hundred sixty-one thousand, eight hundred one".