21146772 has 48 divisors (see below), whose sum is σ = 52395840. Its totient is φ = 6619392.

The previous prime is 21146747. The next prime is 21146779. The reversal of 21146772 is 27764112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21146779) 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, 30898 + ... + 31574.

It is an arithmetic number, because the mean of its divisors is an integer number (1091580).

Almost surely, 2^21146772 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 21146772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26197920).

21146772 is an abundant number, since it is smaller than the sum of its proper divisors (31249068).

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

21146772 is a wasteful number, since it uses less digits than its factorization.

21146772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840 (or 838 counting only the distinct ones).

The product of its digits is 4704, while the sum is 30.

The square root of 21146772 is about 4598.5619491315. The cubic root of 21146772 is about 276.5336765071.

The spelling of 21146772 in words is "twenty-one million, one hundred forty-six thousand, seven hundred seventy-two".