21430365 has 32 divisors (see below), whose sum is σ = 39038976. Its totient is φ = 9936960.

The previous prime is 21430327. The next prime is 21430369. The reversal of 21430365 is 56303412.

It is a happy number.

It is not a de Polignac number, because 21430365 - 2⁶ = 21430301 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430369) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 972 + ... + 6618.

It is an arithmetic number, because the mean of its divisors is an integer number (1219968).

Almost surely, 2^21430365 is an apocalyptic number.

It is an amenable number.

21430365 is a deficient number, since it is larger than the sum of its proper divisors (17608611).

21430365 is a wasteful number, since it uses less digits than its factorization.

21430365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5689.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 21430365 is about 4629.2942226650. The cubic root of 21430365 is about 277.7643613372.

Adding to 21430365 its reverse (56303412), we get a palindrome (77733777).

The spelling of 21430365 in words is "twenty-one million, four hundred thirty thousand, three hundred sixty-five".