1621660320 has 144 divisors (see below), whose sum is σ = 6324514560. Its totient is φ = 370662912.

The previous prime is 1621660301. The next prime is 1621660351. The reversal of 1621660320 is 230661261.

1621660320 is a `hidden beast` number, since 1 + 621 + 6 + 6 + 0 + 32 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70360 + ... + 90519.

It is an arithmetic number, because the mean of its divisors is an integer number (43920240).

Almost surely, 2^1621660320 is an apocalyptic number.

1621660320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621660320 is an abundant number, since it is smaller than the sum of its proper divisors (4702854240).

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

1621660320 is a wasteful number, since it uses less digits than its factorization.

1621660320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160907 (or 160896 counting only the distinct ones).

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

The square root of 1621660320 is about 40269.8438040179. The cubic root of 1621660320 is about 1174.8613857911.

The spelling of 1621660320 in words is "one billion, six hundred twenty-one million, six hundred sixty thousand, three hundred twenty".