21529872 has 240 divisors, whose sum is σ = 77995008. Its totient is φ = 5391360.

The previous prime is 21529787. The next prime is 21529873. The reversal of 21529872 is 27892512.

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 (21529873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 406198 + ... + 406250.

Almost surely, 2^21529872 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 21529872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38997504).

21529872 is an abundant number, since it is smaller than the sum of its proper divisors (56465136).

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

21529872 is a wasteful number, since it uses less digits than its factorization.

21529872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 109 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 21529872 is about 4640.0293102523. The cubic root of 21529872 is about 278.1936094171.

The spelling of 21529872 in words is "twenty-one million, five hundred twenty-nine thousand, eight hundred seventy-two".