21575438 has 8 divisors (see below), whose sum is σ = 32610600. Its totient is φ = 10705240.

The previous prime is 21575423. The next prime is 21575443. The reversal of 21575438 is 83457512.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21575398 and 21575407.

It is a congruent number.

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, 40913 + ... + 41436.

It is an arithmetic number, because the mean of its divisors is an integer number (4076325).

Almost surely, 2^21575438 is an apocalyptic number.

21575438 is a deficient number, since it is larger than the sum of its proper divisors (11035162).

21575438 is a wasteful number, since it uses less digits than its factorization.

21575438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82482.

The product of its digits is 33600, while the sum is 35.

The square root of 21575438 is about 4644.9368133485. The cubic root of 21575438 is about 278.3897282152.

The spelling of 21575438 in words is "twenty-one million, five hundred seventy-five thousand, four hundred thirty-eight".