21485772 has 144 divisors (see below), whose sum is σ = 70866432. Its totient is φ = 5322240.

The previous prime is 21485771. The next prime is 21485797. The reversal of 21485772 is 27758412.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21485771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 63588 + ... + 63924.

It is an arithmetic number, because the mean of its divisors is an integer number (492128).

Almost surely, 2^21485772 is an apocalyptic number.

21485772 is a gapful number since it is divisible by the number (22) 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 21485772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35433216).

21485772 is an abundant number, since it is smaller than the sum of its proper divisors (49380660).

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

21485772 is a wasteful number, since it uses less digits than its factorization.

21485772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 383 counting only the distinct ones).

The product of its digits is 31360, while the sum is 36.

The square root of 21485772 is about 4635.2747491384. The cubic root of 21485772 is about 278.0035366940.

The spelling of 21485772 in words is "twenty-one million, four hundred eighty-five thousand, seven hundred seventy-two".