1620646544 has 20 divisors (see below), whose sum is σ = 3425457840. Its totient is φ = 736657440.

The previous prime is 1620646541. The next prime is 1620646603. The reversal of 1620646544 is 4456460261.

It is a junction number, because it is equal to n+sod(n) for n = 1620646498 and 1620646507.

It is not an unprimeable number, because it can be changed into a prime (1620646541) 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, 4603934 + ... + 4604285.

It is an arithmetic number, because the mean of its divisors is an integer number (171272892).

Almost surely, 2^1620646544 is an apocalyptic number.

It is an amenable number.

1620646544 is an abundant number, since it is smaller than the sum of its proper divisors (1804811296).

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

1620646544 is a wasteful number, since it uses less digits than its factorization.

1620646544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9208238 (or 9208232 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 1620646544 is about 40257.2545511986. The cubic root of 1620646544 is about 1174.6165144206.

The spelling of 1620646544 in words is "one billion, six hundred twenty million, six hundred forty-six thousand, five hundred forty-four".