1720138379 has 2 divisors, whose sum is σ = 1720138380. Its totient is φ = 1720138378.

The previous prime is 1720138367. The next prime is 1720138411. The reversal of 1720138379 is 9738310271.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720138379 is a prime.

It is not a weakly prime, because it can be changed into another prime (1720138339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860069189 + 860069190.

It is an arithmetic number, because the mean of its divisors is an integer number (860069190).

Almost surely, 2^1720138379 is an apocalyptic number.

1720138379 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720138379 is an equidigital number, since it uses as much as digits as its factorization.

1720138379 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 1720138379 is about 41474.5509800890. The cubic root of 1720138379 is about 1198.1774135410.

The spelling of 1720138379 in words is "one billion, seven hundred twenty million, one hundred thirty-eight thousand, three hundred seventy-nine".