21620998 has 8 divisors (see below), whose sum is σ = 37064592. Its totient is φ = 9266136.

The previous prime is 21620953. The next prime is 21620999. The reversal of 21620998 is 89902612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620999) by changing a digit.

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, 772165 + ... + 772192.

It is an arithmetic number, because the mean of its divisors is an integer number (4633074).

Almost surely, 2^21620998 is an apocalyptic number.

21620998 is a deficient number, since it is larger than the sum of its proper divisors (15443594).

21620998 is a wasteful number, since it uses less digits than its factorization.

21620998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544366.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 21620998 is about 4649.8384918188. The cubic root of 21620998 is about 278.5855453101.

The spelling of 21620998 in words is "twenty-one million, six hundred twenty thousand, nine hundred ninety-eight".