21239519120 has 20 divisors (see below), whose sum is σ = 49381882140. Its totient is φ = 8495807616.

The previous prime is 21239519101. The next prime is 21239519137. The reversal of 21239519120 is 2191593212.

It can be written as a sum of positive squares in 2 ways, for example, as 9132478096 + 12107041024 = 95564^2 + 110032^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×21239519120² (a number of 21 digits) contains 22 as substring.

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 3 ways as a sum of consecutive naturals, for example, 132746915 + ... + 132747074.

It is an arithmetic number, because the mean of its divisors is an integer number (2469094107).

Almost surely, 2^21239519120 is an apocalyptic number.

21239519120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21239519120 is an abundant number, since it is smaller than the sum of its proper divisors (28142363020).

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

21239519120 is a wasteful number, since it uses less digits than its factorization.

21239519120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265494002 (or 265493996 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 35.

The spelling of 21239519120 in words is "twenty-one billion, two hundred thirty-nine million, five hundred nineteen thousand, one hundred twenty".