1621539216 has 80 divisors (see below), whose sum is σ = 5077561920. Its totient is φ = 491374080.

The previous prime is 1621539191. The next prime is 1621539223. The reversal of 1621539216 is 6129351261.

1621539216 is a `hidden beast` number, since 1 + 621 + 5 + 3 + 9 + 21 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 165865 + ... + 175368.

It is an arithmetic number, because the mean of its divisors is an integer number (63469524).

Almost surely, 2^1621539216 is an apocalyptic number.

1621539216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1621539216 is an abundant number, since it is smaller than the sum of its proper divisors (3456022704).

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

1621539216 is a wasteful number, since it uses less digits than its factorization.

1621539216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341261 (or 341249 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 1621539216 is about 40268.3401197516. The cubic root of 1621539216 is about 1174.8321392316.

The spelling of 1621539216 in words is "one billion, six hundred twenty-one million, five hundred thirty-nine thousand, two hundred sixteen".