21346405 has 8 divisors (see below), whose sum is σ = 26964000. Its totient is φ = 16178256.

The previous prime is 21346397. The next prime is 21346411. The reversal of 21346405 is 50464312.

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

It is a cyclic number.

It is not a de Polignac number, because 21346405 - 2³ = 21346397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21346405.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 112255 + ... + 112444.

It is an arithmetic number, because the mean of its divisors is an integer number (3370500).

Almost surely, 2^21346405 is an apocalyptic number.

It is an amenable number.

21346405 is a deficient number, since it is larger than the sum of its proper divisors (5617595).

21346405 is a wasteful number, since it uses less digits than its factorization.

21346405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224723.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 21346405 is about 4620.2169862464. The cubic root of 21346405 is about 277.4011443461.

The spelling of 21346405 in words is "twenty-one million, three hundred forty-six thousand, four hundred five".