21379369 has 12 divisors (see below), whose sum is σ = 23729860. Its totient is φ = 19245600.

The previous prime is 21379363. The next prime is 21379399. The reversal of 21379369 is 96397312.

It can be written as a sum of positive squares in 2 ways, for example, as 15681600 + 5697769 = 3960^2 + 2387^2 .

It is not a de Polignac number, because 21379369 - 2¹³ = 21371177 is a prime.

It is a super-2 number, since 2×21379369² = 914154837676322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21379363) 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 11 ways as a sum of consecutive naturals, for example, 12379 + ... + 13999.

Almost surely, 2^21379369 is an apocalyptic number.

It is an amenable number.

21379369 is a deficient number, since it is larger than the sum of its proper divisors (2350491).

21379369 is a wasteful number, since it uses less digits than its factorization.

21379369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1752 (or 1741 counting only the distinct ones).

The product of its digits is 61236, while the sum is 40.

The square root of 21379369 is about 4623.7829750108. The cubic root of 21379369 is about 277.5438623413.

The spelling of 21379369 in words is "twenty-one million, three hundred seventy-nine thousand, three hundred sixty-nine".