1621533516 has 48 divisors (see below), whose sum is σ = 3863311200. Its totient is φ = 529165312.

The previous prime is 1621533509. The next prime is 1621533517. The reversal of 1621533516 is 6153351261.

It is a super-2 number, since 2×1621533516² = 5258741887022644512, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1621533517) 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 15 ways as a sum of consecutive naturals, for example, 321220 + ... + 326228.

It is an arithmetic number, because the mean of its divisors is an integer number (80485650).

Almost surely, 2^1621533516 is an apocalyptic number.

It is an amenable number.

1621533516 is an abundant number, since it is smaller than the sum of its proper divisors (2241777684).

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

1621533516 is a wasteful number, since it uses less digits than its factorization.

1621533516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5578 (or 5576 counting only the distinct ones).

The product of its digits is 16200, while the sum is 33.

The square root of 1621533516 is about 40268.2693444851. The cubic root of 1621533516 is about 1174.8307626484.

Adding to 1621533516 its reverse (6153351261), we get a palindrome (7774884777).

The spelling of 1621533516 in words is "one billion, six hundred twenty-one million, five hundred thirty-three thousand, five hundred sixteen".