21421368 has 32 divisors (see below), whose sum is σ = 59504400. Its totient is φ = 7140384.

The previous prime is 21421333. The next prime is 21421373. The reversal of 21421368 is 86312412.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

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 7 ways as a sum of consecutive naturals, for example, 49371 + ... + 49802.

Almost surely, 2^21421368 is an apocalyptic number.

It is an amenable number.

21421368 is an abundant number, since it is smaller than the sum of its proper divisors (38083032).

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

21421368 is a wasteful number, since it uses less digits than its factorization.

21421368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99188 (or 99178 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21421368 is about 4628.3223742518. The cubic root of 21421368 is about 277.7254851015.

The spelling of 21421368 in words is "twenty-one million, four hundred twenty-one thousand, three hundred sixty-eight".