1620840646 has 8 divisors (see below), whose sum is σ = 2434692240. Its totient is φ = 809276568.

The previous prime is 1620840643. The next prime is 1620840671. The reversal of 1620840646 is 6460480261.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620840643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 570106 + ... + 572941.

It is an arithmetic number, because the mean of its divisors is an integer number (304336530).

Almost surely, 2^1620840646 is an apocalyptic number.

1620840646 is a deficient number, since it is larger than the sum of its proper divisors (813851594).

1620840646 is a wasteful number, since it uses less digits than its factorization.

1620840646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1143758.

The product of its (nonzero) digits is 55296, while the sum is 37.

The square root of 1620840646 is about 40259.6652494777. The cubic root of 1620840646 is about 1174.6634064699.

The spelling of 1620840646 in words is "one billion, six hundred twenty million, eight hundred forty thousand, six hundred forty-six".