1620322920 has 128 divisors (see below), whose sum is σ = 5457110400. Its totient is φ = 427603968.

The previous prime is 1620322919. The next prime is 1620322937. The reversal of 1620322920 is 292230261.

1620322920 is a `hidden beast` number, since 1 + 620 + 32 + 2 + 9 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 97027 + ... + 112493.

It is an arithmetic number, because the mean of its divisors is an integer number (42633675).

Almost surely, 2^1620322920 is an apocalyptic number.

1620322920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1620322920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2728555200).

1620322920 is an abundant number, since it is smaller than the sum of its proper divisors (3836787480).

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

1620322920 is a wasteful number, since it uses less digits than its factorization.

1620322920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15584 (or 15574 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 1620322920 is about 40253.2349010611. The cubic root of 1620322920 is about 1174.5383235278.

The spelling of 1620322920 in words is "one billion, six hundred twenty million, three hundred twenty-two thousand, nine hundred twenty".