221245425 has 72 divisors (see below), whose sum is σ = 417056640. Its totient is φ = 116251200.

The previous prime is 221245421. The next prime is 221245447. The reversal of 221245425 is 524542122.

It is not a de Polignac number, because 221245425 - 2² = 221245421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (221245421) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 479695 + ... + 480155.

Almost surely, 2^221245425 is an apocalyptic number.

221245425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221245425 is a deficient number, since it is larger than the sum of its proper divisors (195811215).

221245425 is an equidigital number, since it uses as much as digits as its factorization.

221245425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565 (or 548 counting only the distinct ones).

The product of its digits is 6400, while the sum is 27.

The square root of 221245425 is about 14874.3209929059. The cubic root of 221245425 is about 604.8180815881.

Adding to 221245425 its reverse (524542122), we get a palindrome (745787547).

The spelling of 221245425 in words is "two hundred twenty-one million, two hundred forty-five thousand, four hundred twenty-five".