1640542 has 4 divisors (see below), whose sum is σ = 2460816. Its totient is φ = 820270.

The previous prime is 1640539. The next prime is 1640549. The reversal of 1640542 is 2450461.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410134 + ... + 410137.

It is an arithmetic number, because the mean of its divisors is an integer number (615204).

2^1640542 is an apocalyptic number.

1640542 is a deficient number, since it is larger than the sum of its proper divisors (820274).

1640542 is an equidigital number, since it uses as much as digits as its factorization.

1640542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820273.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 1640542 is about 1280.8364454527. The cubic root of 1640542 is about 117.9403605545.

The spelling of 1640542 in words is "one million, six hundred forty thousand, five hundred forty-two".