1398642805 has 8 divisors (see below), whose sum is σ = 1918138752. Its totient is φ = 959069328.

The previous prime is 1398642803. The next prime is 1398642863. The reversal of 1398642805 is 5082468931.

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

It is not a de Polignac number, because 1398642805 - 2¹ = 1398642803 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1398642803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19980577 + ... + 19980646.

It is an arithmetic number, because the mean of its divisors is an integer number (239767344).

Almost surely, 2^1398642805 is an apocalyptic number.

It is an amenable number.

1398642805 is a deficient number, since it is larger than the sum of its proper divisors (519495947).

1398642805 is an equidigital number, since it uses as much as digits as its factorization.

1398642805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39961235.

The product of its (nonzero) digits is 414720, while the sum is 46.

The square root of 1398642805 is about 37398.4331891057. The cubic root of 1398642805 is about 1118.3273301951.

The spelling of 1398642805 in words is "one billion, three hundred ninety-eight million, six hundred forty-two thousand, eight hundred five".