21058409520 has 120 divisors (see below), whose sum is σ = 71025248736. Its totient is φ = 5591430144.

The previous prime is 21058409513. The next prime is 21058409521. The reversal of 21058409520 is 2590485012.

21058409520 is a `hidden beast` number, since 21 + 0 + 584 + 0 + 9 + 52 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×21058409520² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21058409521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104997 + ... + 230523.

Almost surely, 2^21058409520 is an apocalyptic number.

21058409520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21058409520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35512624368).

21058409520 is an abundant number, since it is smaller than the sum of its proper divisors (49966839216).

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

21058409520 is a wasteful number, since it uses less digits than its factorization.

21058409520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125779 (or 125770 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 21058409520 in words is "twenty-one billion, fifty-eight million, four hundred nine thousand, five hundred twenty".