21092406 has 16 divisors (see below), whose sum is σ = 42254784. Its totient is φ = 7019144.

The previous prime is 21092399. The next prime is 21092411. The reversal of 21092406 is 60429012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1525 + ... + 6671.

It is an arithmetic number, because the mean of its divisors is an integer number (2640924).

Almost surely, 2^21092406 is an apocalyptic number.

21092406 is an abundant number, since it is smaller than the sum of its proper divisors (21162378).

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

21092406 is a wasteful number, since it uses less digits than its factorization.

21092406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5835.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 21092406 is about 4592.6469492004. The cubic root of 21092406 is about 276.2964940206.

It can be divided in two parts, 2 and 1092406, that multiplied together give a palindrome (2184812).

The spelling of 21092406 in words is "twenty-one million, ninety-two thousand, four hundred six".