21229998 has 32 divisors (see below), whose sum is σ = 43755552. Its totient is φ = 6864000.

The previous prime is 21229979. The next prime is 21230017. The reversal of 21229998 is 89992212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21229979) and next prime (21230017).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31788 + ... + 32448.

It is an arithmetic number, because the mean of its divisors is an integer number (1367361).

Almost surely, 2^21229998 is an apocalyptic number.

21229998 is an abundant number, since it is smaller than the sum of its proper divisors (22525554).

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

21229998 is a wasteful number, since it uses less digits than its factorization.

21229998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820.

The product of its digits is 46656, while the sum is 42.

The square root of 21229998 is about 4607.6021963707. The cubic root of 21229998 is about 276.8959802666.

The spelling of 21229998 in words is "twenty-one million, two hundred twenty-nine thousand, nine hundred ninety-eight".