1381979639 has 2 divisors, whose sum is σ = 1381979640. Its totient is φ = 1381979638.

The previous prime is 1381979617. The next prime is 1381979663. The reversal of 1381979639 is 9369791831.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1381979639 is a prime.

It is a super-2 number, since 2×1381979639² = 3819735445221140642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1381979539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690989819 + 690989820.

It is an arithmetic number, because the mean of its divisors is an integer number (690989820).

Almost surely, 2^1381979639 is an apocalyptic number.

1381979639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381979639 is an equidigital number, since it uses as much as digits as its factorization.

1381979639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 56.

The square root of 1381979639 is about 37174.9867383971. The cubic root of 1381979639 is about 1113.8683952566.

The spelling of 1381979639 in words is "one billion, three hundred eighty-one million, nine hundred seventy-nine thousand, six hundred thirty-nine".