225521816 has 32 divisors (see below), whose sum is σ = 456744960. Its totient is φ = 103775232.

The previous prime is 225521809. The next prime is 225521827. The reversal of 225521816 is 618125522.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33641 + ... + 39783.

It is an arithmetic number, because the mean of its divisors is an integer number (14273280).

Almost surely, 2^225521816 is an apocalyptic number.

225521816 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

225521816 is an abundant number, since it is smaller than the sum of its proper divisors (231223144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

225521816 is a wasteful number, since it uses less digits than its factorization.

225521816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6515 (or 6511 counting only the distinct ones).

The product of its digits is 9600, while the sum is 32.

The square root of 225521816 is about 15017.3837934575. The cubic root of 225521816 is about 608.6900276966.

The spelling of 225521816 in words is "two hundred twenty-five million, five hundred twenty-one thousand, eight hundred sixteen".