1978771047618 has 16 divisors (see below), whose sum is σ = 3968881761600. Its totient is φ = 657700404816.

The previous prime is 1978771047599. The next prime is 1978771047641. The reversal of 1978771047618 is 8167401778791.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 472483830 + ... + 472488017.

It is an arithmetic number, because the mean of its divisors is an integer number (248055110100).

Almost surely, 2^{1978771047618} is an apocalyptic number.

1978771047618 is an abundant number, since it is smaller than the sum of its proper divisors (1990110713982).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978771047618 is a wasteful number, since it uses less digits than its factorization.

1978771047618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944972201.

The product of its (nonzero) digits is 33191424, while the sum is 66.

The spelling of 1978771047618 in words is "one trillion, nine hundred seventy-eight billion, seven hundred seventy-one million, forty-seven thousand, six hundred eighteen".