21347219520 has 896 divisors, whose sum is σ = 86377881600. Its totient is φ = 4979128320.

The previous prime is 21347219503. The next prime is 21347219521. The reversal of 21347219520 is 2591274312.

21347219520 is a `hidden beast` number, since 21 + 34 + 72 + 19 + 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 (21347219521) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 361817251 + ... + 361817309.

Almost surely, 2^21347219520 is an apocalyptic number.

21347219520 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 21347219520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43188940800).

21347219520 is an abundant number, since it is smaller than the sum of its proper divisors (65030662080).

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

21347219520 is an equidigital number, since it uses as much as digits as its factorization.

21347219520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21347219520 in words is "twenty-one billion, three hundred forty-seven million, two hundred nineteen thousand, five hundred twenty".