21229418 has 16 divisors (see below), whose sum is σ = 36457344. Its totient is φ = 9082320.

The previous prime is 21229409. The next prime is 21229463. The reversal of 21229418 is 81492212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10571 + ... + 12417.

It is an arithmetic number, because the mean of its divisors is an integer number (2278584).

Almost surely, 2^21229418 is an apocalyptic number.

21229418 is a deficient number, since it is larger than the sum of its proper divisors (15227926).

21229418 is a wasteful number, since it uses less digits than its factorization.

21229418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2677.

The product of its digits is 2304, while the sum is 29.

The square root of 21229418 is about 4607.5392564795. The cubic root of 21229418 is about 276.8934586596.

The spelling of 21229418 in words is "twenty-one million, two hundred twenty-nine thousand, four hundred eighteen".