1381978697 has 4 divisors (see below), whose sum is σ = 1507613136. Its totient is φ = 1256344260.

The previous prime is 1381978651. The next prime is 1381978709. The reversal of 1381978697 is 7968791831.

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 1381978697 - 2¹⁴ = 1381962313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1381978597) 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, 62817203 + ... + 62817224.

It is an arithmetic number, because the mean of its divisors is an integer number (376903284).

Almost surely, 2^1381978697 is an apocalyptic number.

It is an amenable number.

1381978697 is a deficient number, since it is larger than the sum of its proper divisors (125634439).

1381978697 is a wasteful number, since it uses less digits than its factorization.

1381978697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125634438.

The product of its digits is 4572288, while the sum is 59.

The square root of 1381978697 is about 37174.9740685854. The cubic root of 1381978697 is about 1113.8681421742.

The spelling of 1381978697 in words is "one billion, three hundred eighty-one million, nine hundred seventy-eight thousand, six hundred ninety-seven".