21521204152 has 192 divisors, whose sum is σ = 50557996800. Its totient is φ = 8543969280.

The previous prime is 21521204147. The next prime is 21521204171. The reversal of 21521204152 is 25140212512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 60966408 + ... + 60966760.

It is an arithmetic number, because the mean of its divisors is an integer number (263322900).

Almost surely, 2^21521204152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21521204152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25278998400).

21521204152 is an abundant number, since it is smaller than the sum of its proper divisors (29036792648).

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

21521204152 is a wasteful number, since it uses less digits than its factorization.

21521204152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606 (or 595 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21521204152 its reverse (25140212512), we get a palindrome (46661416664).

The spelling of 21521204152 in words is "twenty-one billion, five hundred twenty-one million, two hundred four thousand, one hundred fifty-two".