371661 has 4 divisors (see below), whose sum is σ = 495552. Its totient is φ = 247772.

The previous prime is 371639. The next prime is 371663. The reversal of 371661 is 166173.

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 371661 - 2¹⁵ = 338893 is a prime.

It is a super-3 number, since 3×371661³ = 154014719054633343, which contains 333 as substring.

It is a D-number.

371661 is a lucky number.

It is a plaindrome in base 16.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (371663) 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, 61941 + ... + 61946.

It is an arithmetic number, because the mean of its divisors is an integer number (123888).

2³⁷¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

371661 is a deficient number, since it is larger than the sum of its proper divisors (123891).

371661 is a wasteful number, since it uses less digits than its factorization.

371661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123890.

The product of its digits is 756, while the sum is 24.

The square root of 371661 is about 609.6400577390. The cubic root of 371661 is about 71.8978102775.

The spelling of 371661 in words is "three hundred seventy-one thousand, six hundred sixty-one".