21420088 has 16 divisors (see below), whose sum is σ = 40405680. Its totient is φ = 10645248.

The previous prime is 21420079. The next prime is 21420097. The reversal of 21420088 is 88002412.

It is an interprime number because it is at equal distance from previous prime (21420079) and next prime (21420097).

It is a congruent number.

It is an unprimeable number.

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, 6681 + ... + 9352.

It is an arithmetic number, because the mean of its divisors is an integer number (2525355).

Almost surely, 2^21420088 is an apocalyptic number.

It is an amenable number.

21420088 is a deficient number, since it is larger than the sum of its proper divisors (18985592).

21420088 is a wasteful number, since it uses less digits than its factorization.

21420088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16206 (or 16202 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 21420088 is about 4628.1840931406. The cubic root of 21420088 is about 277.7199533088.

It can be divided in two parts, 214 and 20088, that added together give a palindrome (20302).

The spelling of 21420088 in words is "twenty-one million, four hundred twenty thousand, eighty-eight".