1381263257 has 4 divisors (see below), whose sum is σ = 1506832656. Its totient is φ = 1255693860.

The previous prime is 1381263253. The next prime is 1381263259. The reversal of 1381263257 is 7523621831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1381263257 - 2² = 1381263253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1381263257.

It is not an unprimeable number, because it can be changed into a prime (1381263251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62784683 + ... + 62784704.

It is an arithmetic number, because the mean of its divisors is an integer number (376708164).

Almost surely, 2^1381263257 is an apocalyptic number.

It is an amenable number.

1381263257 is a deficient number, since it is larger than the sum of its proper divisors (125569399).

1381263257 is a wasteful number, since it uses less digits than its factorization.

1381263257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125569398.

The product of its digits is 60480, while the sum is 38.

The square root of 1381263257 is about 37165.3502203329. The cubic root of 1381263257 is about 1113.6758952694.

The spelling of 1381263257 in words is "one billion, three hundred eighty-one million, two hundred sixty-three thousand, two hundred fifty-seven".