21347406 has 48 divisors (see below), whose sum is σ = 48542208. Its totient is φ = 6771600.

The previous prime is 21347371. The next prime is 21347419. The reversal of 21347406 is 60474312.

21347406 is a `hidden beast` number, since 213 + 47 + 406 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21347406.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37101 + ... + 37671.

It is an arithmetic number, because the mean of its divisors is an integer number (1011296).

Almost surely, 2^21347406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21347406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24271104).

21347406 is an abundant number, since it is smaller than the sum of its proper divisors (27194802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21347406 is a wasteful number, since it uses less digits than its factorization.

21347406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 21347406 is about 4620.3253132220. The cubic root of 21347406 is about 277.4054803488.

The spelling of 21347406 in words is "twenty-one million, three hundred forty-seven thousand, four hundred six".