21420512 has 12 divisors (see below), whose sum is σ = 42171696. Its totient is φ = 10710240.

The previous prime is 21420499. The next prime is 21420541. The reversal of 21420512 is 21502412.

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, 334664 + ... + 334727.

It is an arithmetic number, because the mean of its divisors is an integer number (3514308).

Almost surely, 2^21420512 is an apocalyptic number.

It is an amenable number.

21420512 is a deficient number, since it is larger than the sum of its proper divisors (20751184).

21420512 is an equidigital number, since it uses as much as digits as its factorization.

21420512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 669401 (or 669393 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21420512 is about 4628.2298992163. The cubic root of 21420512 is about 277.7217857396.

Adding to 21420512 its reverse (21502412), we get a palindrome (42922924).

The spelling of 21420512 in words is "twenty-one million, four hundred twenty thousand, five hundred twelve".