21667752 has 96 divisors (see below), whose sum is σ = 63273600. Its totient is φ = 6676992.

The previous prime is 21667739. The next prime is 21667757. The reversal of 21667752 is 25776612.

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

It is not an unprimeable number, because it can be changed into a prime (21667757) 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 23 ways as a sum of consecutive naturals, for example, 64128 + ... + 64464.

It is an arithmetic number, because the mean of its divisors is an integer number (659100).

Almost surely, 2^21667752 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 21667752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31636800).

21667752 is an abundant number, since it is smaller than the sum of its proper divisors (41605848).

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

21667752 is a wasteful number, since it uses less digits than its factorization.

21667752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 408 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 21667752 is about 4654.8632632979. The cubic root of 21667752 is about 278.7862084384.

The spelling of 21667752 in words is "twenty-one million, six hundred sixty-seven thousand, seven hundred fifty-two".