21010072 has 8 divisors (see below), whose sum is σ = 39393900. Its totient is φ = 10505032.

The previous prime is 21010069. The next prime is 21010097. The reversal of 21010072 is 27001012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1313122 + ... + 1313137.

Almost surely, 2^21010072 is an apocalyptic number.

It is an amenable number.

21010072 is a deficient number, since it is larger than the sum of its proper divisors (18383828).

21010072 is a wasteful number, since it uses less digits than its factorization.

21010072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2626265 (or 2626261 counting only the distinct ones).

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 21010072 is about 4583.6745085139. The cubic root of 21010072 is about 275.9365183412.

Adding to 21010072 its reverse (27001012), we get a palindrome (48011084).

The spelling of 21010072 in words is "twenty-one million, ten thousand, seventy-two".