21375156 has 48 divisors (see below), whose sum is σ = 55093248. Its totient is φ = 6396000.

The previous prime is 21375143. The next prime is 21375157. The reversal of 21375156 is 65157312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21375157) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9981 + ... + 11931.

It is an arithmetic number, because the mean of its divisors is an integer number (1147776).

Almost surely, 2^21375156 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 21375156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27546624).

21375156 is an abundant number, since it is smaller than the sum of its proper divisors (33718092).

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

21375156 is a wasteful number, since it uses less digits than its factorization.

21375156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2052 (or 2050 counting only the distinct ones).

The product of its digits is 6300, while the sum is 30.

The square root of 21375156 is about 4623.3273732237. The cubic root of 21375156 is about 277.5256302924.

The spelling of 21375156 in words is "twenty-one million, three hundred seventy-five thousand, one hundred fifty-six".