1621659616 has 24 divisors (see below), whose sum is σ = 3212239464. Its totient is φ = 805852800.

The previous prime is 1621659601. The next prime is 1621659617. The reversal of 1621659616 is 6169561261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621659617) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 150235 + ... + 160666.

It is an arithmetic number, because the mean of its divisors is an integer number (133843311).

Almost surely, 2^1621659616 is an apocalyptic number.

1621659616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1621659616 is a deficient number, since it is larger than the sum of its proper divisors (1590579848).

1621659616 is a wasteful number, since it uses less digits than its factorization.

1621659616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311074 (or 311066 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 1621659616 is about 40269.8350629848. The cubic root of 1621659616 is about 1174.8612157797.

The spelling of 1621659616 in words is "one billion, six hundred twenty-one million, six hundred fifty-nine thousand, six hundred sixteen".