21088406 has 8 divisors (see below), whose sum is σ = 31694664. Its totient is φ = 10523520.

The previous prime is 21088393. The next prime is 21088421. The reversal of 21088406 is 60488012.

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

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, 9035 + ... + 11126.

It is an arithmetic number, because the mean of its divisors is an integer number (3961833).

Almost surely, 2^21088406 is an apocalyptic number.

21088406 is a deficient number, since it is larger than the sum of its proper divisors (10606258).

21088406 is a wasteful number, since it uses less digits than its factorization.

21088406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20686.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 21088406 is about 4592.2114498355. The cubic root of 21088406 is about 276.2790271362.

The spelling of 21088406 in words is "twenty-one million, eighty-eight thousand, four hundred six".