1340381657 has 4 divisors (see below), whose sum is σ = 1410928080. Its totient is φ = 1269835236.

The previous prime is 1340381593. The next prime is 1340381687. The reversal of 1340381657 is 7561830431.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7561830431 = 10399 ⋅727169.

It is a cyclic number.

It is not a de Polignac number, because 1340381657 - 2⁶ = 1340381593 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 1340381657.

It is not an unprimeable number, because it can be changed into a prime (1340381687) 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, 35273183 + ... + 35273220.

It is an arithmetic number, because the mean of its divisors is an integer number (352732020).

Almost surely, 2^1340381657 is an apocalyptic number.

It is an amenable number.

1340381657 is a deficient number, since it is larger than the sum of its proper divisors (70546423).

1340381657 is an equidigital number, since it uses as much as digits as its factorization.

1340381657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70546422.

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

The square root of 1340381657 is about 36611.2231016665. The cubic root of 1340381657 is about 1102.5784298804.

The spelling of 1340381657 in words is "one billion, three hundred forty million, three hundred eighty-one thousand, six hundred fifty-seven".