1978441656 has 16 divisors (see below), whose sum is σ = 4946104200. Its totient is φ = 659480544.

The previous prime is 1978441651. The next prime is 1978441679. The reversal of 1978441656 is 6561448791.

It is a junction number, because it is equal to n+sod(n) for n = 1978441599 and 1978441608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978441651) 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, 41217511 + ... + 41217558.

Almost surely, 2^1978441656 is an apocalyptic number.

It is an amenable number.

1978441656 is an abundant number, since it is smaller than the sum of its proper divisors (2967662544).

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

1978441656 is a wasteful number, since it uses less digits than its factorization.

1978441656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82435078 (or 82435074 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 51.

The square root of 1978441656 is about 44479.6768873156. The cubic root of 1978441656 is about 1255.3777175582.

The spelling of 1978441656 in words is "one billion, nine hundred seventy-eight million, four hundred forty-one thousand, six hundred fifty-six".