1375661 has 4 divisors (see below), whose sum is σ = 1572192. Its totient is φ = 1179132.

The previous prime is 1375639. The next prime is 1375669. The reversal of 1375661 is 1665731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1375661 - 2⁶ = 1375597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1375669) 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, 98255 + ... + 98268.

It is an arithmetic number, because the mean of its divisors is an integer number (393048).

2^1375661 is an apocalyptic number.

It is an amenable number.

1375661 is a deficient number, since it is larger than the sum of its proper divisors (196531).

1375661 is an equidigital number, since it uses as much as digits as its factorization.

1375661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196530.

The product of its digits is 3780, while the sum is 29.

The square root of 1375661 is about 1172.8857574376. The cubic root of 1375661 is about 111.2168204720.

The spelling of 1375661 in words is "one million, three hundred seventy-five thousand, six hundred sixty-one".