21210654 has 16 divisors (see below), whose sum is σ = 42497280. Its totient is φ = 7057560.

The previous prime is 21210649. The next prime is 21210691. The reversal of 21210654 is 45601212.

It is a self number, because there is not a number n which added to its sum of digits gives 21210654.

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, 859 + ... + 6569.

It is an arithmetic number, because the mean of its divisors is an integer number (2656080).

Almost surely, 2^21210654 is an apocalyptic number.

21210654 is an abundant number, since it is smaller than the sum of its proper divisors (21286626).

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

21210654 is a wasteful number, since it uses less digits than its factorization.

21210654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6335.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21210654 is about 4605.5025784381. The cubic root of 21210654 is about 276.8118555376.

Adding to 21210654 its reverse (45601212), we get a palindrome (66811866).

The spelling of 21210654 in words is "twenty-one million, two hundred ten thousand, six hundred fifty-four".