1978648279 has 8 divisors (see below), whose sum is σ = 2058318000. Its totient is φ = 1899741312.

The previous prime is 1978648271. The next prime is 1978648303. The reversal of 1978648279 is 9728468791.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1978648279 - 2³ = 1978648271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978648271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185394 + ... + 195775.

It is an arithmetic number, because the mean of its divisors is an integer number (257289750).

Almost surely, 2^1978648279 is an apocalyptic number.

1978648279 is a deficient number, since it is larger than the sum of its proper divisors (79669721).

1978648279 is a wasteful number, since it uses less digits than its factorization.

1978648279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381377.

The product of its digits is 12192768, while the sum is 61.

The square root of 1978648279 is about 44481.9994941774. Note that the first 3 decimals coincide. The cubic root of 1978648279 is about 1255.4214187679.

The spelling of 1978648279 in words is "one billion, nine hundred seventy-eight million, six hundred forty-eight thousand, two hundred seventy-nine".