21486925 has 6 divisors (see below), whose sum is σ = 26643818. Its totient is φ = 17189520.

The previous prime is 21486923. The next prime is 21486931. The reversal of 21486925 is 52968412.

It can be written as a sum of positive squares in 3 ways, for example, as 5470921 + 16016004 = 2339^2 + 4002^2 .

It is not a de Polignac number, because 21486925 - 2¹ = 21486923 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 (21486923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 429714 + ... + 429763.

Almost surely, 2^21486925 is an apocalyptic number.

21486925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21486925 is a deficient number, since it is larger than the sum of its proper divisors (5156893).

21486925 is an equidigital number, since it uses as much as digits as its factorization.

21486925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859487 (or 859482 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The square root of 21486925 is about 4635.3991198170. The cubic root of 21486925 is about 278.0085094785.

It can be divided in two parts, 214 and 86925, that multiplied together give a triangular number (18601950 = T₆₀₉₉).

The spelling of 21486925 in words is "twenty-one million, four hundred eighty-six thousand, nine hundred twenty-five".