1978567377 has 4 divisors (see below), whose sum is σ = 2638089840. Its totient is φ = 1319044916.

The previous prime is 1978567247. The next prime is 1978567379. The reversal of 1978567377 is 7737658791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7737658791 = 3 ⋅2579219597.

It is a cyclic number.

It is not a de Polignac number, because 1978567377 - 2⁸ = 1978567121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1978567377.

It is not an unprimeable number, because it can be changed into a prime (1978567379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329761227 + ... + 329761232.

It is an arithmetic number, because the mean of its divisors is an integer number (659522460).

Almost surely, 2^1978567377 is an apocalyptic number.

It is an amenable number.

1978567377 is a deficient number, since it is larger than the sum of its proper divisors (659522463).

1978567377 is an equidigital number, since it uses as much as digits as its factorization.

1978567377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659522462.

The product of its digits is 15558480, while the sum is 60.

The square root of 1978567377 is about 44481.0901057966. The cubic root of 1978567377 is about 1255.4043081830.

The spelling of 1978567377 in words is "one billion, nine hundred seventy-eight million, five hundred sixty-seven thousand, three hundred seventy-seven".