21260370 has 32 divisors (see below), whose sum is σ = 54027648. Its totient is φ = 5335808.

The previous prime is 21260359. The next prime is 21260377. The reversal of 21260370 is 7306212.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21260377) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20334 + ... + 21353.

It is an arithmetic number, because the mean of its divisors is an integer number (1688364).

Almost surely, 2^21260370 is an apocalyptic number.

21260370 is an abundant number, since it is smaller than the sum of its proper divisors (32767278).

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

21260370 is a wasteful number, since it uses less digits than its factorization.

21260370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41714.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21260370 is about 4610.8968758800. The cubic root of 21260370 is about 277.0279613978.

Adding to 21260370 its reverse (7306212), we get a palindrome (28566582).

The spelling of 21260370 in words is "twenty-one million, two hundred sixty thousand, three hundred seventy".