21263470 has 16 divisors (see below), whose sum is σ = 40289040. Its totient is φ = 8057664.

The previous prime is 21263453. The next prime is 21263471. The reversal of 21263470 is 7436212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21263471) 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, 55767 + ... + 56146.

It is an arithmetic number, because the mean of its divisors is an integer number (2518065).

Almost surely, 2^21263470 is an apocalyptic number.

21263470 is a deficient number, since it is larger than the sum of its proper divisors (19025570).

21263470 is a wasteful number, since it uses less digits than its factorization.

21263470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111939.

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 21263470 is about 4611.2330238235. The cubic root of 21263470 is about 277.0414253363.

Adding to 21263470 its reverse (7436212), we get a palindrome (28699682).

The spelling of 21263470 in words is "twenty-one million, two hundred sixty-three thousand, four hundred seventy".