21307270 has 8 divisors (see below), whose sum is σ = 38353104. Its totient is φ = 8522904.

The previous prime is 21307243. The next prime is 21307271. The reversal of 21307270 is 7270312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21307271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1065354 + ... + 1065373.

It is an arithmetic number, because the mean of its divisors is an integer number (4794138).

Almost surely, 2^21307270 is an apocalyptic number.

21307270 is a deficient number, since it is larger than the sum of its proper divisors (17045834).

21307270 is a wasteful number, since it uses less digits than its factorization.

21307270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2130734.

The product of its (nonzero) digits is 588, while the sum is 22.

The square root of 21307270 is about 4615.9798526423. The cubic root of 21307270 is about 277.2315180505.

Adding to 21307270 its reverse (7270312), we get a palindrome (28577582).

The spelling of 21307270 in words is "twenty-one million, three hundred seven thousand, two hundred seventy".