257720445 has 12 divisors (see below), whose sum is σ = 446715516. Its totient is φ = 137450880.

The previous prime is 257720423. The next prime is 257720461. The reversal of 257720445 is 544027752.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 41100921 + 216619524 = 6411^2 + 14718^2 .

It is not a de Polignac number, because 257720445 - 2⁶ = 257720381 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2863516 + ... + 2863605.

It is an arithmetic number, because the mean of its divisors is an integer number (37226293).

Almost surely, 2^257720445 is an apocalyptic number.

It is an amenable number.

257720445 is a deficient number, since it is larger than the sum of its proper divisors (188995071).

257720445 is a wasteful number, since it uses less digits than its factorization.

257720445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5727132 (or 5727129 counting only the distinct ones).

The product of its (nonzero) digits is 78400, while the sum is 36.

The square root of 257720445 is about 16053.6738785862. The cubic root of 257720445 is about 636.3796608797.

The spelling of 257720445 in words is "two hundred fifty-seven million, seven hundred twenty thousand, four hundred forty-five".