21469855 has 16 divisors (see below), whose sum is σ = 28794528. Its totient is φ = 15232000.

The previous prime is 21469853. The next prime is 21469897. The reversal of 21469855 is 55896412.

It is not a de Polignac number, because 21469855 - 2¹ = 21469853 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 (21469853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2506 + ... + 7015.

It is an arithmetic number, because the mean of its divisors is an integer number (1799658).

Almost surely, 2^21469855 is an apocalyptic number.

21469855 is a deficient number, since it is larger than the sum of its proper divisors (7324673).

21469855 is a wasteful number, since it uses less digits than its factorization.

21469855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9578.

The product of its digits is 86400, while the sum is 40.

The square root of 21469855 is about 4633.5574885826. The cubic root of 21469855 is about 277.9348699278.

The spelling of 21469855 in words is "twenty-one million, four hundred sixty-nine thousand, eight hundred fifty-five".