21130033520 has 40 divisors (see below), whose sum is σ = 49401815760. Its totient is φ = 8404789760.

The previous prime is 21130033517. The next prime is 21130033531. The reversal of 21130033520 is 2533003112.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21130033492 and 21130033501.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 723461 + ... + 752100.

It is an arithmetic number, because the mean of its divisors is an integer number (1235045394).

Almost surely, 2^21130033520 is an apocalyptic number.

21130033520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130033520 is an abundant number, since it is smaller than the sum of its proper divisors (28271782240).

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

21130033520 is a wasteful number, since it uses less digits than its factorization.

21130033520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475753 (or 1475747 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 20.

Adding to 21130033520 its reverse (2533003112), we get a palindrome (23663036632).

The spelling of 21130033520 in words is "twenty-one billion, one hundred thirty million, thirty-three thousand, five hundred twenty".