21253654 has 8 divisors (see below), whose sum is σ = 31947408. Its totient is φ = 10604520.

The previous prime is 21253649. The next prime is 21253657. The reversal of 21253654 is 45635212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9937 + ... + 11884.

It is an arithmetic number, because the mean of its divisors is an integer number (3993426).

Almost surely, 2^21253654 is an apocalyptic number.

21253654 is a deficient number, since it is larger than the sum of its proper divisors (10693754).

21253654 is a wasteful number, since it uses less digits than its factorization.

21253654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22310.

The product of its digits is 7200, while the sum is 28.

The square root of 21253654 is about 4610.1685435567. The cubic root of 21253654 is about 276.9987879367.

Adding to 21253654 its reverse (45635212), we get a palindrome (66888866).

The spelling of 21253654 in words is "twenty-one million, two hundred fifty-three thousand, six hundred fifty-four".