1640161 has 4 divisors (see below), whose sum is σ = 1642752. Its totient is φ = 1637572.

The previous prime is 1640147. The next prime is 1640167. The reversal of 1640161 is 1610461.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1640161 - 2⁷ = 1640033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640167) 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, 360 + ... + 1846.

It is an arithmetic number, because the mean of its divisors is an integer number (410688).

2^1640161 is an apocalyptic number.

It is an amenable number.

1640161 is a deficient number, since it is larger than the sum of its proper divisors (2591).

1640161 is a wasteful number, since it uses less digits than its factorization.

1640161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2590.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 1640161 is about 1280.6877058831. The cubic root of 1640161 is about 117.9312296786.

The spelling of 1640161 in words is "one million, six hundred forty thousand, one hundred sixty-one".