21273613 has 8 divisors (see below), whose sum is σ = 22654080. Its totient is φ = 19907520.

The previous prime is 21273611. The next prime is 21273641. The reversal of 21273613 is 31637212.

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 21273613 - 2¹ = 21273611 is a prime.

It is a super-2 number, since 2×21273613² = 905133220147538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21273611) 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, 453 + ... + 6538.

It is an arithmetic number, because the mean of its divisors is an integer number (2831760).

Almost surely, 2^21273613 is an apocalyptic number.

It is an amenable number.

21273613 is a deficient number, since it is larger than the sum of its proper divisors (1380467).

21273613 is a wasteful number, since it uses less digits than its factorization.

21273613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7187.

The product of its digits is 1512, while the sum is 25.

The square root of 21273613 is about 4612.3327069933. The cubic root of 21273613 is about 277.0854693311.

The spelling of 21273613 in words is "twenty-one million, two hundred seventy-three thousand, six hundred thirteen".