21272013 has 12 divisors (see below), whose sum is σ = 35115808. Its totient is φ = 12155400.

The previous prime is 21272011. The next prime is 21272021. The reversal of 21272013 is 31027212.

It is not a de Polignac number, because 21272013 - 2¹ = 21272011 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168763 + ... + 168888.

Almost surely, 2^21272013 is an apocalyptic number.

It is an amenable number.

21272013 is a deficient number, since it is larger than the sum of its proper divisors (13843795).

21272013 is a wasteful number, since it uses less digits than its factorization.

21272013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337664 (or 337661 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21272013 is about 4612.1592557066. The cubic root of 21272013 is about 277.0785225740.

Adding to 21272013 its reverse (31027212), we get a palindrome (52299225).

The spelling of 21272013 in words is "twenty-one million, two hundred seventy-two thousand, thirteen".