21270370 has 16 divisors (see below), whose sum is σ = 41767488. Its totient is φ = 7734640.

The previous prime is 21270323. The next prime is 21270373. The reversal of 21270370 is 7307212.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21270373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96574 + ... + 96793.

It is an arithmetic number, because the mean of its divisors is an integer number (2610468).

Almost surely, 2^21270370 is an apocalyptic number.

21270370 is a deficient number, since it is larger than the sum of its proper divisors (20497118).

21270370 is a wasteful number, since it uses less digits than its factorization.

21270370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193385.

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

The square root of 21270370 is about 4611.9811361279. The cubic root of 21270370 is about 277.0713887603.

Adding to 21270370 its reverse (7307212), we get a palindrome (28577582).

The spelling of 21270370 in words is "twenty-one million, two hundred seventy thousand, three hundred seventy".