21142586520 has 768 divisors, whose sum is σ = 84942950400. Its totient is φ = 4653158400.

The previous prime is 21142586501. The next prime is 21142586527. The reversal of 21142586520 is 2568524112.

21142586520 is a `hidden beast` number, since 2 + 11 + 42 + 5 + 86 + 520 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142586527) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 68868207 + ... + 68868513.

It is an arithmetic number, because the mean of its divisors is an integer number (110602800).

Almost surely, 2^21142586520 is an apocalyptic number.

21142586520 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 21142586520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42471475200).

21142586520 is an abundant number, since it is smaller than the sum of its proper divisors (63800363880).

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

21142586520 is a wasteful number, since it uses less digits than its factorization.

21142586520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The spelling of 21142586520 in words is "twenty-one billion, one hundred forty-two million, five hundred eighty-six thousand, five hundred twenty".