1978360785 has 12 divisors (see below), whose sum is σ = 3429158772. Its totient is φ = 1055125728.

The previous prime is 1978360781. The next prime is 1978360789. The reversal of 1978360785 is 5870638791.

It is an interprime number because it is at equal distance from previous prime (1978360781) and next prime (1978360789).

It can be written as a sum of positive squares in 2 ways, for example, as 1481249169 + 497111616 = 38487^2 + 22296^2 .

It is not a de Polignac number, because 1978360785 - 2² = 1978360781 is a prime.

It is a super-2 number, since 2×1978360785² = 7827822791251632450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1978360781) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 21981742 + ... + 21981831.

It is an arithmetic number, because the mean of its divisors is an integer number (285763231).

Almost surely, 2^1978360785 is an apocalyptic number.

1978360785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1978360785 is a deficient number, since it is larger than the sum of its proper divisors (1450797987).

1978360785 is a wasteful number, since it uses less digits than its factorization.

1978360785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43963584 (or 43963581 counting only the distinct ones).

The product of its (nonzero) digits is 2540160, while the sum is 54.

The square root of 1978360785 is about 44478.7677999290. The cubic root of 1978360785 is about 1255.3606123390.

The spelling of 1978360785 in words is "one billion, nine hundred seventy-eight million, three hundred sixty thousand, seven hundred eighty-five".