1978257488449 has 16 divisors (see below), whose sum is σ = 2206634526720. Its totient is φ = 1758411729360.

The previous prime is 1978257488447. The next prime is 1978257488479. The reversal of 1978257488449 is 9448847528791.

It is not a de Polignac number, because 1978257488449 - 2¹ = 1978257488447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978257488443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10961347 + ... + 11140360.

It is an arithmetic number, because the mean of its divisors is an integer number (137914657920).

Almost surely, 2^{1978257488449} is an apocalyptic number.

It is an amenable number.

1978257488449 is a deficient number, since it is larger than the sum of its proper divisors (228377038271).

1978257488449 is a wasteful number, since it uses less digits than its factorization.

1978257488449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22101900.

The product of its digits is 1300561920, while the sum is 76.

The spelling of 1978257488449 in words is "one trillion, nine hundred seventy-eight billion, two hundred fifty-seven million, four hundred eighty-eight thousand, four hundred forty-nine".