225970991 has 4 divisors (see below), whose sum is σ = 226001184. Its totient is φ = 225940800.

The previous prime is 225970981. The next prime is 225971027. The reversal of 225970991 is 199079522.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 199079522 = 2 ⋅99539761.

It is a cyclic number.

It is not a de Polignac number, because 225970991 - 2¹⁴ = 225954607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225970931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5471 + ... + 21951.

It is an arithmetic number, because the mean of its divisors is an integer number (56500296).

Almost surely, 2^225970991 is an apocalyptic number.

225970991 is a deficient number, since it is larger than the sum of its proper divisors (30193).

225970991 is a wasteful number, since it uses less digits than its factorization.

225970991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30192.

The product of its (nonzero) digits is 102060, while the sum is 44.

The square root of 225970991 is about 15032.3315224219. The cubic root of 225970991 is about 609.0938718886.

The spelling of 225970991 in words is "two hundred twenty-five million, nine hundred seventy thousand, nine hundred ninety-one".