21053088 has 144 divisors (see below), whose sum is σ = 71386560. Its totient is φ = 5913216.

The previous prime is 21053077. The next prime is 21053093. The reversal of 21053088 is 88035012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 356803 + ... + 356861.

It is an arithmetic number, because the mean of its divisors is an integer number (495740).

Almost surely, 2^21053088 is an apocalyptic number.

21053088 is a gapful number since it is divisible by the number (28) 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 21053088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35693280).

21053088 is an abundant number, since it is smaller than the sum of its proper divisors (50333472).

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

21053088 is an equidigital number, since it uses as much as digits as its factorization.

21053088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21053088 is about 4588.3644144728. The cubic root of 21053088 is about 276.1247073491.

The spelling of 21053088 in words is "twenty-one million, fifty-three thousand, eighty-eight".