21472138 has 8 divisors (see below), whose sum is σ = 32893632. Its totient is φ = 10507596.

The previous prime is 21472127. The next prime is 21472163. The reversal of 21472138 is 83127412.

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

It is a super-2 number, since 2×21472138² = 922105420582088, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114120 + ... + 114307.

It is an arithmetic number, because the mean of its divisors is an integer number (4111704).

Almost surely, 2^21472138 is an apocalyptic number.

21472138 is a deficient number, since it is larger than the sum of its proper divisors (11421494).

21472138 is a wasteful number, since it uses less digits than its factorization.

21472138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228476.

The product of its digits is 2688, while the sum is 28.

The square root of 21472138 is about 4633.8038370220. The cubic root of 21472138 is about 277.9447209930.

The spelling of 21472138 in words is "twenty-one million, four hundred seventy-two thousand, one hundred thirty-eight".