1257915138 has 16 divisors (see below), whose sum is σ = 2517695136. Its totient is φ = 418994240.

The previous prime is 1257915101. The next prime is 1257915143. The reversal of 1257915138 is 8315197521.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1257915138.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68856 + ... + 85187.

It is an arithmetic number, because the mean of its divisors is an integer number (157355946).

Almost surely, 2^1257915138 is an apocalyptic number.

1257915138 is an abundant number, since it is smaller than the sum of its proper divisors (1259779998).

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

1257915138 is a wasteful number, since it uses less digits than its factorization.

1257915138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155409.

The product of its digits is 75600, while the sum is 42.

The square root of 1257915138 is about 35467.0993739268. The cubic root of 1257915138 is about 1079.4862491341.

The spelling of 1257915138 in words is "one billion, two hundred fifty-seven million, nine hundred fifteen thousand, one hundred thirty-eight".