21478124 has 12 divisors (see below), whose sum is σ = 38224200. Its totient is φ = 10556928.

The previous prime is 21478117. The next prime is 21478147. The reversal of 21478124 is 42187412.

It is a super-2 number, since 2×21478124² = 922619621118752, 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, 45269 + ... + 45740.

It is an arithmetic number, because the mean of its divisors is an integer number (3185350).

Almost surely, 2^21478124 is an apocalyptic number.

It is an amenable number.

21478124 is a deficient number, since it is larger than the sum of its proper divisors (16746076).

21478124 is a wasteful number, since it uses less digits than its factorization.

21478124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91072 (or 91070 counting only the distinct ones).

The product of its digits is 3584, while the sum is 29.

The square root of 21478124 is about 4634.4496976448. The cubic root of 21478124 is about 277.9705470583.

The spelling of 21478124 in words is "twenty-one million, four hundred seventy-eight thousand, one hundred twenty-four".