21120654 has 32 divisors (see below), whose sum is σ = 43870464. Its totient is φ = 6773760.

The previous prime is 21120637. The next prime is 21120661. The reversal of 21120654 is 45602112.

It is a self number, because there is not a number n which added to its sum of digits gives 21120654.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17742 + ... + 18894.

It is an arithmetic number, because the mean of its divisors is an integer number (1370952).

Almost surely, 2^21120654 is an apocalyptic number.

21120654 is an abundant number, since it is smaller than the sum of its proper divisors (22749810).

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

21120654 is a wasteful number, since it uses less digits than its factorization.

21120654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1272.

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

The square root of 21120654 is about 4595.7212709215. The cubic root of 21120654 is about 276.4197823382.

Adding to 21120654 its reverse (45602112), we get a palindrome (66722766).

The spelling of 21120654 in words is "twenty-one million, one hundred twenty thousand, six hundred fifty-four".