1257721160 has 32 divisors (see below), whose sum is σ = 2841636600. Its totient is φ = 500997120.

The previous prime is 1257721151. The next prime is 1257721163. The reversal of 1257721160 is 611277521.

It can be written as a sum of positive squares in 4 ways, for example, as 1142845636 + 114875524 = 33806^2 + 10718^2 .

It is not an unprimeable number, because it can be changed into a prime (1257721163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55595 + ... + 74874.

Almost surely, 2^1257721160 is an apocalyptic number.

1257721160 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1257721160 is an abundant number, since it is smaller than the sum of its proper divisors (1583915440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1257721160 is a wasteful number, since it uses less digits than its factorization.

1257721160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130721 (or 130717 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 32.

The square root of 1257721160 is about 35464.3646496028. The cubic root of 1257721160 is about 1079.4307585472.

Adding to 1257721160 its reverse (611277521), we get a palindrome (1868998681).

The spelling of 1257721160 in words is "one billion, two hundred fifty-seven million, seven hundred twenty-one thousand, one hundred sixty".