21629268 has 60 divisors (see below), whose sum is σ = 56982772. Its totient is φ = 7153920.

The previous prime is 21629233. The next prime is 21629281. The reversal of 21629268 is 86292612.

It is a happy number.

21629268 is a `hidden beast` number, since 2 + 1 + 629 + 26 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9809424 + 11819844 = 3132^2 + 3438^2 .

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

21629268 is a modest number, since divided by 29268 gives 216 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 77946 + ... + 78222.

Almost surely, 2^21629268 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 21629268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28491386).

21629268 is an abundant number, since it is smaller than the sum of its proper divisors (35353504).

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

21629268 is a wasteful number, since it uses less digits than its factorization.

21629268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534 (or 523 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 21629268 is about 4650.7276849973. The cubic root of 21629268 is about 278.6210603031.

The spelling of 21629268 in words is "twenty-one million, six hundred twenty-nine thousand, two hundred sixty-eight".