225721994 has 4 divisors (see below), whose sum is σ = 338582994. Its totient is φ = 112860996.

The previous prime is 225721973. The next prime is 225721997. The reversal of 225721994 is 499127522.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 224250625 + 1471369 = 14975^2 + 1213^2 .

It is not an unprimeable number, because it can be changed into a prime (225721997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 56430497 + ... + 56430500.

Almost surely, 2^225721994 is an apocalyptic number.

225721994 is a deficient number, since it is larger than the sum of its proper divisors (112861000).

225721994 is a wasteful number, since it uses less digits than its factorization.

225721994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112860999.

The product of its digits is 90720, while the sum is 41.

The square root of 225721994 is about 15024.0471910867. The cubic root of 225721994 is about 608.8700698778.

The spelling of 225721994 in words is "two hundred twenty-five million, seven hundred twenty-one thousand, nine hundred ninety-four".