225556691 has 2 divisors, whose sum is σ = 225556692. Its totient is φ = 225556690.

The previous prime is 225556687. The next prime is 225556729. The reversal of 225556691 is 196655522.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 225556691 - 2² = 225556687 is a prime.

It is not a weakly prime, because it can be changed into another prime (225556601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112778345 + 112778346.

It is an arithmetic number, because the mean of its divisors is an integer number (112778346).

Almost surely, 2^225556691 is an apocalyptic number.

225556691 is a deficient number, since it is larger than the sum of its proper divisors (1).

225556691 is an equidigital number, since it uses as much as digits as its factorization.

225556691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 41.

The square root of 225556691 is about 15018.5449028859. The cubic root of 225556691 is about 608.7214022970.

The spelling of 225556691 in words is "two hundred twenty-five million, five hundred fifty-six thousand, six hundred ninety-one".