21420276 has 12 divisors (see below), whose sum is σ = 49980672. Its totient is φ = 7140088.

The previous prime is 21420263. The next prime is 21420281. The reversal of 21420276 is 67202412.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 892500 + ... + 892523.

It is an arithmetic number, because the mean of its divisors is an integer number (4165056).

Almost surely, 2^21420276 is an apocalyptic number.

It is an amenable number.

21420276 is an abundant number, since it is smaller than the sum of its proper divisors (28560396).

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

21420276 is a wasteful number, since it uses less digits than its factorization.

21420276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1785030 (or 1785028 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21420276 is about 4628.2044034377. The cubic root of 21420276 is about 277.7207658047.

Adding to 21420276 its reverse (67202412), we get a palindrome (88622688).

The spelling of 21420276 in words is "twenty-one million, four hundred twenty thousand, two hundred seventy-six".