1645611620 has 24 divisors (see below), whose sum is σ = 3458246400. Its totient is φ = 657775712.

The previous prime is 1645611601. The next prime is 1645611623. The reversal of 1645611620 is 261165461.

It is not an unprimeable number, because it can be changed into a prime (1645611623) 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 7 ways as a sum of consecutive naturals, for example, 191 + ... + 57369.

It is an arithmetic number, because the mean of its divisors is an integer number (144093600).

Almost surely, 2^1645611620 is an apocalyptic number.

1645611620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1645611620 is an abundant number, since it is smaller than the sum of its proper divisors (1812634780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645611620 is a wasteful number, since it uses less digits than its factorization.

1645611620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58627 (or 58625 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 1645611620 is about 40566.1388352404. The cubic root of 1645611620 is about 1180.6172247304.

The spelling of 1645611620 in words is "one billion, six hundred forty-five million, six hundred eleven thousand, six hundred twenty".