21264370 has 16 divisors (see below), whose sum is σ = 38345688. Its totient is φ = 8490240.

The previous prime is 21264361. The next prime is 21264371. The reversal of 21264370 is 7346212.

It can be written as a sum of positive squares in 4 ways, for example, as 21150801 + 113569 = 4599^2 + 337^2 .

It is not an unprimeable number, because it can be changed into a prime (21264371) 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, 5002 + ... + 8218.

Almost surely, 2^21264370 is an apocalyptic number.

21264370 is a deficient number, since it is larger than the sum of its proper divisors (17081318).

21264370 is a wasteful number, since it uses less digits than its factorization.

21264370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3885.

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

The square root of 21264370 is about 4611.3306105722. The cubic root of 21264370 is about 277.0453339766.

The spelling of 21264370 in words is "twenty-one million, two hundred sixty-four thousand, three hundred seventy".