21154272 has 24 divisors (see below), whose sum is σ = 55530216. Its totient is φ = 7051392.

The previous prime is 21154207. The next prime is 21154283. The reversal of 21154272 is 27245112.

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110083 + ... + 110274.

It is an arithmetic number, because the mean of its divisors is an integer number (2313759).

Almost surely, 2^21154272 is an apocalyptic number.

It is an amenable number.

21154272 is an abundant number, since it is smaller than the sum of its proper divisors (34375944).

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

21154272 is a wasteful number, since it uses less digits than its factorization.

21154272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220370 (or 220362 counting only the distinct ones).

The product of its digits is 1120, while the sum is 24.

The square root of 21154272 is about 4599.3773491637. The cubic root of 21154272 is about 276.5663648284.

Adding to 21154272 its reverse (27245112), we get a palindrome (48399384).

The spelling of 21154272 in words is "twenty-one million, one hundred fifty-four thousand, two hundred seventy-two".