21525353220 has 96 divisors (see below), whose sum is σ = 70180846848. Its totient is φ = 4827244032.

The previous prime is 21525353207. The next prime is 21525353249. The reversal of 21525353220 is 2235352512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 461239 + ... + 505758.

It is an arithmetic number, because the mean of its divisors is an integer number (731050488).

Almost surely, 2^21525353220 is an apocalyptic number.

21525353220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21525353220 is an abundant number, since it is smaller than the sum of its proper divisors (48655493628).

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

21525353220 is a wasteful number, since it uses less digits than its factorization.

21525353220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 967069 (or 967067 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

The spelling of 21525353220 in words is "twenty-one billion, five hundred twenty-five million, three hundred fifty-three thousand, two hundred twenty".