21153012 has 12 divisors (see below), whose sum is σ = 49357056. Its totient is φ = 7051000.

The previous prime is 21152983. The next prime is 21153017. The reversal of 21153012 is 21035112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21152982 and 21153000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153017) 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 3 ways as a sum of consecutive naturals, for example, 881364 + ... + 881387.

It is an arithmetic number, because the mean of its divisors is an integer number (4113088).

Almost surely, 2^21153012 is an apocalyptic number.

It is an amenable number.

21153012 is an abundant number, since it is smaller than the sum of its proper divisors (28204044).

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

21153012 is a wasteful number, since it uses less digits than its factorization.

21153012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762758 (or 1762756 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21153012 is about 4599.2403720615. The cubic root of 21153012 is about 276.5608737304.

Adding to 21153012 its reverse (21035112), we get a palindrome (42188124).

The spelling of 21153012 in words is "twenty-one million, one hundred fifty-three thousand, twelve".