21463375 has 8 divisors (see below), whose sum is σ = 26786448. Its totient is φ = 17170600.

The previous prime is 21463373. The next prime is 21463417. The reversal of 21463375 is 57336412.

It is not a de Polignac number, because 21463375 - 2¹ = 21463373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21463373) 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, 85729 + ... + 85978.

It is an arithmetic number, because the mean of its divisors is an integer number (3348306).

Almost surely, 2^21463375 is an apocalyptic number.

21463375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21463375 is a deficient number, since it is larger than the sum of its proper divisors (5323073).

21463375 is an equidigital number, since it uses as much as digits as its factorization.

21463375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171722 (or 171712 counting only the distinct ones).

The product of its digits is 15120, while the sum is 31.

The square root of 21463375 is about 4632.8581890664. The cubic root of 21463375 is about 277.9069051499.

Adding to 21463375 its reverse (57336412), we get a palindrome (78799787).

The spelling of 21463375 in words is "twenty-one million, four hundred sixty-three thousand, three hundred seventy-five".