21464375 has 20 divisors (see below), whose sum is σ = 27310008. Its totient is φ = 16860000.

The previous prime is 21464371. The next prime is 21464393. The reversal of 21464375 is 57346412.

It is not a de Polignac number, because 21464375 - 2² = 21464371 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 (21464371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 37844 + ... + 38406.

Almost surely, 2^21464375 is an apocalyptic number.

21464375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21464375 is a deficient number, since it is larger than the sum of its proper divisors (5845633).

21464375 is an frugal number, since it uses more digits than its factorization.

21464375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644 (or 629 counting only the distinct ones).

The product of its digits is 20160, while the sum is 32.

The square root of 21464375 is about 4632.9661125460. The cubic root of 21464375 is about 277.9112210693.

The spelling of 21464375 in words is "twenty-one million, four hundred sixty-four thousand, three hundred seventy-five".