1621135500 has 48 divisors (see below), whose sum is σ = 4720750944. Its totient is φ = 432302400.

The previous prime is 1621135471. The next prime is 1621135511. The reversal of 1621135500 is 55311261.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 538879 + ... + 541878.

It is an arithmetic number, because the mean of its divisors is an integer number (98348978).

Almost surely, 2^1621135500 is an apocalyptic number.

1621135500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1621135500 is an abundant number, since it is smaller than the sum of its proper divisors (3099615444).

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

1621135500 is a wasteful number, since it uses less digits than its factorization.

1621135500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080779 (or 1080767 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 1621135500 is about 40263.3269862290. The cubic root of 1621135500 is about 1174.7346314861.

Adding to 1621135500 its reverse (55311261), we get a palindrome (1676446761).

The spelling of 1621135500 in words is "one billion, six hundred twenty-one million, one hundred thirty-five thousand, five hundred".