21379575 has 48 divisors (see below), whose sum is σ = 40798976. Its totient is φ = 9676800.

The previous prime is 21379571. The next prime is 21379609. The reversal of 21379575 is 57597312.

It is not a de Polignac number, because 21379575 - 2² = 21379571 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 (21379571) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 101220 + ... + 101430.

Almost surely, 2^21379575 is an apocalyptic number.

21379575 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21379575 is a deficient number, since it is larger than the sum of its proper divisors (19419401).

21379575 is a wasteful number, since it uses less digits than its factorization.

21379575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424 (or 419 counting only the distinct ones).

The product of its digits is 66150, while the sum is 39.

The square root of 21379575 is about 4623.8052510892. The cubic root of 21379575 is about 277.5447537592.

The spelling of 21379575 in words is "twenty-one million, three hundred seventy-nine thousand, five hundred seventy-five".