1381240257 has 8 divisors (see below), whose sum is σ = 1847576640. Its totient is φ = 917865360.

The previous prime is 1381240253. The next prime is 1381240271. The reversal of 1381240257 is 7520421831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1381240257 - 2² = 1381240253 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1381240253) 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, 739282 + ... + 741147.

It is an arithmetic number, because the mean of its divisors is an integer number (230947080).

Almost surely, 2^1381240257 is an apocalyptic number.

It is an amenable number.

1381240257 is a deficient number, since it is larger than the sum of its proper divisors (466336383).

1381240257 is a wasteful number, since it uses less digits than its factorization.

1381240257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480743.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 1381240257 is about 37165.0407910445. The cubic root of 1381240257 is about 1113.6697138053.

The spelling of 1381240257 in words is "one billion, three hundred eighty-one million, two hundred forty thousand, two hundred fifty-seven".