21270225 has 24 divisors (see below), whose sum is σ = 35836992. Its totient is φ = 11128000.

The previous prime is 21270217. The next prime is 21270233. The reversal of 21270225 is 52207212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21270217) and next prime (21270233).

It is not a de Polignac number, because 21270225 - 2³ = 21270217 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1300 + ... + 6650.

It is an arithmetic number, because the mean of its divisors is an integer number (1493208).

Almost surely, 2^21270225 is an apocalyptic number.

21270225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21270225 is a deficient number, since it is larger than the sum of its proper divisors (14566767).

21270225 is a wasteful number, since it uses less digits than its factorization.

21270225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5417 (or 5412 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21270225 is about 4611.9654161756. The cubic root of 21270225 is about 277.0707591608.

Adding to 21270225 its reverse (52207212), we get a palindrome (73477437).

The spelling of 21270225 in words is "twenty-one million, two hundred seventy thousand, two hundred twenty-five".