21612052 has 36 divisors (see below), whose sum is σ = 47518240. Its totient is φ = 8418960.

The previous prime is 21612037. The next prime is 21612061. The reversal of 21612052 is 25021612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 199 + ... + 6577.

Almost surely, 2^21612052 is an apocalyptic number.

21612052 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21612052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23759120).

21612052 is an abundant number, since it is smaller than the sum of its proper divisors (25906188).

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

21612052 is a wasteful number, since it uses less digits than its factorization.

21612052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6412 (or 6399 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21612052 is about 4648.8764233952. The cubic root of 21612052 is about 278.5471170794.

Adding to 21612052 its reverse (25021612), we get a palindrome (46633664).

The spelling of 21612052 in words is "twenty-one million, six hundred twelve thousand, fifty-two".