21272673 has 8 divisors (see below), whose sum is σ = 28483200. Its totient is φ = 14121968.

The previous prime is 21272621. The next prime is 21272681. The reversal of 21272673 is 37627212.

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

It is a cyclic number.

It is not a de Polignac number, because 21272673 - 2²¹ = 19175521 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21272673.

It is not an unprimeable number, because it can be changed into a prime (21272683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14118 + ... + 15551.

It is an arithmetic number, because the mean of its divisors is an integer number (3560400).

Almost surely, 2^21272673 is an apocalyptic number.

It is an amenable number.

21272673 is a deficient number, since it is larger than the sum of its proper divisors (7210527).

21272673 is a wasteful number, since it uses less digits than its factorization.

21272673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29911.

The product of its digits is 7056, while the sum is 30.

The square root of 21272673 is about 4612.2308051528. The cubic root of 21272673 is about 277.0813881535.

Adding to 21272673 its reverse (37627212), we get a palindrome (58899885).

It can be divided in two parts, 21272 and 673, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21272673 in words is "twenty-one million, two hundred seventy-two thousand, six hundred seventy-three".