1257121507 has 4 divisors (see below), whose sum is σ = 1258070176. Its totient is φ = 1256172840.

The previous prime is 1257121501. The next prime is 1257121513. The reversal of 1257121507 is 7051217521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7051217521 = 109 ⋅64690069.

It is an interprime number because it is at equal distance from previous prime (1257121501) and next prime (1257121513).

It is a cyclic number.

It is not a de Polignac number, because 1257121507 - 2³ = 1257121499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1257121501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 472344 + ... + 474997.

It is an arithmetic number, because the mean of its divisors is an integer number (314517544).

Almost surely, 2^1257121507 is an apocalyptic number.

1257121507 is a deficient number, since it is larger than the sum of its proper divisors (948669).

1257121507 is an equidigital number, since it uses as much as digits as its factorization.

1257121507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948668.

The product of its (nonzero) digits is 4900, while the sum is 31.

The square root of 1257121507 is about 35455.9093382189. The cubic root of 1257121507 is about 1079.2591818865.

The spelling of 1257121507 in words is "one billion, two hundred fifty-seven million, one hundred twenty-one thousand, five hundred seven".