21161952 has 96 divisors (see below), whose sum is σ = 70560000. Its totient is φ = 6044544.

The previous prime is 21161951. The next prime is 21161963. The reversal of 21161952 is 25916112.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161951) 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, 4299 + ... + 7797.

It is an arithmetic number, because the mean of its divisors is an integer number (735000).

Almost surely, 2^21161952 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 21161952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35280000).

21161952 is an abundant number, since it is smaller than the sum of its proper divisors (49398048).

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

21161952 is a wasteful number, since it uses less digits than its factorization.

21161952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3525 (or 3511 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 21161952 is about 4600.2121690200. The cubic root of 21161952 is about 276.5998296638.

The spelling of 21161952 in words is "twenty-one million, one hundred sixty-one thousand, nine hundred fifty-two".