1978398835 has 8 divisors (see below), whose sum is σ = 2713232736. Its totient is φ = 1356616320.

The previous prime is 1978398757. The next prime is 1978398839. The reversal of 1978398835 is 5388938791.

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

It is not a de Polignac number, because 1978398835 - 2¹⁵ = 1978366067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978398839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28262806 + ... + 28262875.

It is an arithmetic number, because the mean of its divisors is an integer number (339154092).

Almost surely, 2^1978398835 is an apocalyptic number.

1978398835 is a deficient number, since it is larger than the sum of its proper divisors (734833901).

1978398835 is an equidigital number, since it uses as much as digits as its factorization.

1978398835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56525693.

The product of its digits is 13063680, while the sum is 61.

The square root of 1978398835 is about 44479.1955300453. The cubic root of 1978398835 is about 1255.3686604439.

The spelling of 1978398835 in words is "one billion, nine hundred seventy-eight million, three hundred ninety-eight thousand, eight hundred thirty-five".