21052416 has 176 divisors, whose sum is σ = 70744320. Its totient is φ = 5406720.

The previous prime is 21052411. The next prime is 21052469. The reversal of 21052416 is 61425012.

It is a tau number, because it is divible by the number of its divisors (176).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21052392 and 21052401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 236500 + ... + 236588.

Almost surely, 2^21052416 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 21052416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35372160).

21052416 is an abundant number, since it is smaller than the sum of its proper divisors (49691904).

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

21052416 is a wasteful number, since it uses less digits than its factorization.

21052416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21052416 is about 4588.2911851799. The cubic root of 21052416 is about 276.1217694146.

Adding to 21052416 its reverse (61425012), we get a palindrome (82477428).

The spelling of 21052416 in words is "twenty-one million, fifty-two thousand, four hundred sixteen".