1978338615 has 64 divisors (see below), whose sum is σ = 3679119360. Its totient is φ = 897644160.

The previous prime is 1978338589. The next prime is 1978338623. The reversal of 1978338615 is 5168338791.

It is not a de Polignac number, because 1978338615 - 2⁸ = 1978338359 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 256404 + ... + 264006.

It is an arithmetic number, because the mean of its divisors is an integer number (57486240).

Almost surely, 2^1978338615 is an apocalyptic number.

1978338615 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1978338615 is a deficient number, since it is larger than the sum of its proper divisors (1700780745).

1978338615 is a wasteful number, since it uses less digits than its factorization.

1978338615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7724.

The product of its digits is 1088640, while the sum is 51.

The square root of 1978338615 is about 44478.5185791973. The cubic root of 1978338615 is about 1255.3559230277.

The spelling of 1978338615 in words is "one billion, nine hundred seventy-eight million, three hundred thirty-eight thousand, six hundred fifteen".