21016756 has 12 divisors (see below), whose sum is σ = 38378592. Its totient is φ = 10051448.

The previous prime is 21016753. The next prime is 21016763. The reversal of 21016756 is 65761012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114130 + ... + 114313.

It is an arithmetic number, because the mean of its divisors is an integer number (3198216).

Almost surely, 2^21016756 is an apocalyptic number.

It is an amenable number.

21016756 is a deficient number, since it is larger than the sum of its proper divisors (17361836).

21016756 is a wasteful number, since it uses less digits than its factorization.

21016756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228470 (or 228468 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 21016756 is about 4584.4035598974. The cubic root of 21016756 is about 275.9657767550.

Adding to 21016756 its reverse (65761012), we get a palindrome (86777768).

The spelling of 21016756 in words is "twenty-one million, sixteen thousand, seven hundred fifty-six".