21393120 has 96 divisors (see below), whose sum is σ = 77027328. Its totient is φ = 4889088.

The previous prime is 21393101. The next prime is 21393133. The reversal of 21393120 is 2139312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 177 + ... + 6543.

It is an arithmetic number, because the mean of its divisors is an integer number (802368).

Almost surely, 2^21393120 is an apocalyptic number.

21393120 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 21393120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38513664).

21393120 is an abundant number, since it is smaller than the sum of its proper divisors (55634208).

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

21393120 is a wasteful number, since it uses less digits than its factorization.

21393120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6392 (or 6384 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 21393120 is about 4625.2697218649. The cubic root of 21393120 is about 277.6033540831.

The spelling of 21393120 in words is "twenty-one million, three hundred ninety-three thousand, one hundred twenty".