21266198 has 8 divisors (see below), whose sum is σ = 32084208. Its totient is φ = 10571464.

The previous prime is 21266173. The next prime is 21266207. The reversal of 21266198 is 89166212.

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

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 3 ways as a sum of consecutive naturals, for example, 30386 + ... + 31077.

It is an arithmetic number, because the mean of its divisors is an integer number (4010526).

Almost surely, 2^21266198 is an apocalyptic number.

21266198 is a deficient number, since it is larger than the sum of its proper divisors (10818010).

21266198 is a wasteful number, since it uses less digits than its factorization.

21266198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61638.

The product of its digits is 10368, while the sum is 35.

The square root of 21266198 is about 4611.5288137450. The cubic root of 21266198 is about 277.0532725197.

The spelling of 21266198 in words is "twenty-one million, two hundred sixty-six thousand, one hundred ninety-eight".