1661354 has 4 divisors (see below), whose sum is σ = 2492034. Its totient is φ = 830676.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661354 is 4531661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4531661 = 151 ⋅30011.

It can be written as a sum of positive squares in only one way, i.e., 1630729 + 30625 = 1277^2 + 175^2 .

It is a super-2 number, since 2×1661354² = 5520194226632, which contains 22 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1661353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415337 + ... + 415340.

2^1661354 is an apocalyptic number.

1661354 is a deficient number, since it is larger than the sum of its proper divisors (830680).

1661354 is an equidigital number, since it uses as much as digits as its factorization.

1661354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830679.

The product of its digits is 2160, while the sum is 26.

The square root of 1661354 is about 1288.9352194738. The cubic root of 1661354 is about 118.4369988004.

The spelling of 1661354 in words is "one million, six hundred sixty-one thousand, three hundred fifty-four".