21352572 has 60 divisors (see below), whose sum is σ = 56816760. Its totient is φ = 6990624.

The previous prime is 21352571. The next prime is 21352601. The reversal of 21352572 is 27525312.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21352571) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18558 + ... + 19674.

It is an arithmetic number, because the mean of its divisors is an integer number (946946).

Almost surely, 2^21352572 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 21352572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28408380).

21352572 is an abundant number, since it is smaller than the sum of its proper divisors (35464188).

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

21352572 is a wasteful number, since it uses less digits than its factorization.

21352572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1192 (or 1181 counting only the distinct ones).

The product of its digits is 4200, while the sum is 27.

The square root of 21352572 is about 4620.8843309479. The cubic root of 21352572 is about 277.4278556064.

Adding to 21352572 its reverse (27525312), we get a palindrome (48877884).

The spelling of 21352572 in words is "twenty-one million, three hundred fifty-two thousand, five hundred seventy-two".