161257730 has 16 divisors (see below), whose sum is σ = 294241464. Its totient is φ = 63619200.

The previous prime is 161257721. The next prime is 161257741. The reversal of 161257730 is 37752161.

It can be written as a sum of positive squares in 4 ways, for example, as 161010721 + 247009 = 12689^2 + 497^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109721 + ... + 111180.

Almost surely, 2^161257730 is an apocalyptic number.

161257730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161257730 is a deficient number, since it is larger than the sum of its proper divisors (132983734).

161257730 is a wasteful number, since it uses less digits than its factorization.

161257730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220981.

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 161257730 is about 12698.7294640054. The cubic root of 161257730 is about 544.3023140338.

The spelling of 161257730 in words is "one hundred sixty-one million, two hundred fifty-seven thousand, seven hundred thirty".