21621602 has 8 divisors (see below), whose sum is σ = 32472576. Its totient is φ = 10797412.

The previous prime is 21621577. The next prime is 21621629. The reversal of 21621602 is 20612612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 4538 + ... + 7989.

It is an arithmetic number, because the mean of its divisors is an integer number (4059072).

Almost surely, 2^21621602 is an apocalyptic number.

21621602 is a deficient number, since it is larger than the sum of its proper divisors (10850974).

21621602 is a wasteful number, since it uses less digits than its factorization.

21621602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13392.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21621602 is about 4649.9034398576. The cubic root of 21621602 is about 278.5881394565.

The spelling of 21621602 in words is "twenty-one million, six hundred twenty-one thousand, six hundred two".