21270456 has 96 divisors (see below), whose sum is σ = 60933600. Its totient is φ = 6693120.

The previous prime is 21270439. The next prime is 21270511. The reversal of 21270456 is 65407212.

It is a zygodrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 127285 + ... + 127451.

It is an arithmetic number, because the mean of its divisors is an integer number (634725).

Almost surely, 2^21270456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21270456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30466800).

21270456 is an abundant number, since it is smaller than the sum of its proper divisors (39663144).

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

21270456 is a wasteful number, since it uses less digits than its factorization.

21270456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21270456 is about 4611.9904596606. The cubic root of 21270456 is about 277.0717621766.

Adding to 21270456 its reverse (65407212), we get a palindrome (86677668).

The spelling of 21270456 in words is "twenty-one million, two hundred seventy thousand, four hundred fifty-six".