21061712 has 40 divisors (see below), whose sum is σ = 46949376. Its totient is φ = 8966016.

The previous prime is 21061693. The next prime is 21061717. The reversal of 21061712 is 21716012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061717) 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 7 ways as a sum of consecutive naturals, for example, 18833 + ... + 19919.

Almost surely, 2^21061712 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 21061712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23474688).

21061712 is an abundant number, since it is smaller than the sum of its proper divisors (25887664).

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

21061712 is a wasteful number, since it uses less digits than its factorization.

21061712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1275 (or 1269 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 21061712 is about 4589.3040866781. The cubic root of 21061712 is about 276.1624052931.

Adding to 21061712 its reverse (21716012), we get a palindrome (42777724).

The spelling of 21061712 in words is "twenty-one million, sixty-one thousand, seven hundred twelve".