249945221 has 2 divisors, whose sum is σ = 249945222. Its totient is φ = 249945220.

The previous prime is 249945193. The next prime is 249945257. The reversal of 249945221 is 122549942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 233020225 + 16924996 = 15265^2 + 4114^2 .

It is a cyclic number.

It is not a de Polignac number, because 249945221 - 2²² = 245750917 is a prime.

It is a super-2 number, since 2×249945221² = 124945227001477682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249942221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124972610 + 124972611.

It is an arithmetic number, because the mean of its divisors is an integer number (124972611).

Almost surely, 2^249945221 is an apocalyptic number.

It is an amenable number.

249945221 is a deficient number, since it is larger than the sum of its proper divisors (1).

249945221 is an equidigital number, since it uses as much as digits as its factorization.

249945221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 38.

The square root of 249945221 is about 15809.6559418603. The cubic root of 249945221 is about 629.9145101096.

The spelling of 249945221 in words is "two hundred forty-nine million, nine hundred forty-five thousand, two hundred twenty-one".