21424558 has 4 divisors (see below), whose sum is σ = 32136840. Its totient is φ = 10712278.

The previous prime is 21424549. The next prime is 21424577. The reversal of 21424558 is 85542412.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5356138 + ... + 5356141.

It is an arithmetic number, because the mean of its divisors is an integer number (8034210).

Almost surely, 2^21424558 is an apocalyptic number.

21424558 is a deficient number, since it is larger than the sum of its proper divisors (10712282).

21424558 is a wasteful number, since it uses less digits than its factorization.

21424558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10712281.

The product of its digits is 12800, while the sum is 31.

The square root of 21424558 is about 4628.6669787316. Note that the first 3 decimals coincide. The cubic root of 21424558 is about 277.7392704073.

The spelling of 21424558 in words is "twenty-one million, four hundred twenty-four thousand, five hundred fifty-eight".