1661723 has 8 divisors (see below), whose sum is σ = 1908192. Its totient is φ = 1417536.

The previous prime is 1661713. The next prime is 1661731. The reversal of 1661723 is 3271661.

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 1661723 - 2⁶ = 1661659 is a prime.

It is a super-2 number, since 2×1661723² = 5522646657458, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661692 and 1661701.

It is not an unprimeable number, because it can be changed into a prime (1661713) 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, 1511 + ... + 2367.

It is an arithmetic number, because the mean of its divisors is an integer number (238524).

2^1661723 is an apocalyptic number.

1661723 is a deficient number, since it is larger than the sum of its proper divisors (246469).

1661723 is an equidigital number, since it uses as much as digits as its factorization.

1661723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1141.

The product of its digits is 1512, while the sum is 26.

The square root of 1661723 is about 1289.0783529328. The cubic root of 1661723 is about 118.4457667526.

The spelling of 1661723 in words is "one million, six hundred sixty-one thousand, seven hundred twenty-three".