1978897547 has 16 divisors (see below), whose sum is σ = 2178637440. Its totient is φ = 1782518400.

The previous prime is 1978897511. The next prime is 1978897553. The reversal of 1978897547 is 7457988791.

It is a cyclic number.

It is not a de Polignac number, because 1978897547 - 2¹² = 1978893451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1978897567) 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, 1055603 + ... + 1057475.

It is an arithmetic number, because the mean of its divisors is an integer number (136164840).

Almost surely, 2^1978897547 is an apocalyptic number.

1978897547 is a deficient number, since it is larger than the sum of its proper divisors (199739893).

1978897547 is a wasteful number, since it uses less digits than its factorization.

1978897547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2714.

The product of its digits is 35562240, while the sum is 65.

The square root of 1978897547 is about 44484.8013033665. The cubic root of 1978897547 is about 1255.4741354380.

The spelling of 1978897547 in words is "one billion, nine hundred seventy-eight million, eight hundred ninety-seven thousand, five hundred forty-seven".