21211698 has 8 divisors (see below), whose sum is σ = 42423408. Its totient is φ = 7070564.

The previous prime is 21211643. The next prime is 21211709. The reversal of 21211698 is 89611212.

It is a happy number.

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

21211698 is an admirable number.

It is a super-2 number, since 2×21211698² = 899872264086408, which contains 22 as substring.

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, 1767636 + ... + 1767647.

It is an arithmetic number, because the mean of its divisors is an integer number (5302926).

Almost surely, 2^21211698 is an apocalyptic number.

21211698 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21211698 is a wasteful number, since it uses less digits than its factorization.

21211698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3535288.

The product of its digits is 1728, while the sum is 30.

The square root of 21211698 is about 4605.6159197224. The cubic root of 21211698 is about 276.8163970735.

The spelling of 21211698 in words is "twenty-one million, two hundred eleven thousand, six hundred ninety-eight".