21450225 has 24 divisors (see below), whose sum is σ = 35792352. Its totient is φ = 11334400.

The previous prime is 21450211. The next prime is 21450229. The reversal of 21450225 is 52205412.

It is a happy number.

It is not a de Polignac number, because 21450225 - 2⁶ = 21450161 is a prime.

It is a super-2 number, since 2×21450225² = 920224305101250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7210 + ... + 9740.

It is an arithmetic number, because the mean of its divisors is an integer number (1491348).

Almost surely, 2^21450225 is an apocalyptic number.

21450225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21450225 is a deficient number, since it is larger than the sum of its proper divisors (14342127).

21450225 is a wasteful number, since it uses less digits than its factorization.

21450225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2657 (or 2652 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21450225 is about 4631.4387613354. The cubic root of 21450225 is about 277.8501383338.

Adding to 21450225 its reverse (52205412), we get a palindrome (73655637).

The spelling of 21450225 in words is "twenty-one million, four hundred fifty thousand, two hundred twenty-five".