21710052 has 144 divisors (see below), whose sum is σ = 70779520. Its totient is φ = 5603904.

The previous prime is 21710023. The next prime is 21710057. The reversal of 21710052 is 25001712.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21710057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 461893 + ... + 461939.

Almost surely, 2^21710052 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 21710052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35389760).

21710052 is an abundant number, since it is smaller than the sum of its proper divisors (49069468).

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

21710052 is a wasteful number, since it uses less digits than its factorization.

21710052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 21710052 is about 4659.4046830040. The cubic root of 21710052 is about 278.9675069108.

Adding to 21710052 its reverse (25001712), we get a palindrome (46711764).

The spelling of 21710052 in words is "twenty-one million, seven hundred ten thousand, fifty-two".