2019661 has 8 divisors (see below), whose sum is σ = 2330240. Its totient is φ = 1714608.

The previous prime is 2019659. The next prime is 2019679. The reversal of 2019661 is 1669102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2019661 - 2¹ = 2019659 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2019361) 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, 561 + ... + 2086.

It is an arithmetic number, because the mean of its divisors is an integer number (291280).

2^2019661 is an apocalyptic number.

2019661 is the 821-st hex number.

It is an amenable number.

2019661 is a deficient number, since it is larger than the sum of its proper divisors (310579).

2019661 is a wasteful number, since it uses less digits than its factorization.

2019661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2763.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 2019661 is about 1421.1477755673. The cubic root of 2019661 is about 126.4036146018.

The spelling of 2019661 in words is "two million, nineteen thousand, six hundred sixty-one".