1640091 has 8 divisors (see below), whose sum is σ = 2217040. Its totient is φ = 1078272.

The previous prime is 1640083. The next prime is 1640131. The reversal of 1640091 is 1900461.

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

It is not a de Polignac number, because 1640091 - 2³ = 1640083 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1640021) 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, 3526 + ... + 3963.

It is an arithmetic number, because the mean of its divisors is an integer number (277130).

2^1640091 is an apocalyptic number.

1640091 is a deficient number, since it is larger than the sum of its proper divisors (576949).

1640091 is an equidigital number, since it uses as much as digits as its factorization.

1640091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7565.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1640091 is about 1280.6603765245. The cubic root of 1640091 is about 117.9295519360.

The spelling of 1640091 in words is "one million, six hundred forty thousand, ninety-one".