21147952 has 40 divisors (see below), whose sum is σ = 48346112. Its totient is φ = 8769600.

The previous prime is 21147943. The next prime is 21147967. The reversal of 21147952 is 25974112.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 427 + ... + 6517.

Almost surely, 2^21147952 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 21147952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24173056).

21147952 is an abundant number, since it is smaller than the sum of its proper divisors (27198160).

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

21147952 is a wasteful number, since it uses less digits than its factorization.

21147952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6137 (or 6131 counting only the distinct ones).

The product of its digits is 5040, while the sum is 31.

The square root of 21147952 is about 4598.6902483207. The cubic root of 21147952 is about 276.5388199819.

The spelling of 21147952 in words is "twenty-one million, one hundred forty-seven thousand, nine hundred fifty-two".