1928645978 has 24 divisors (see below), whose sum is σ = 3372120000. Its totient is φ = 824885208.

The previous prime is 1928645921. The next prime is 1928645981. The reversal of 1928645978 is 8795468291.

It is a hoax number, since the sum of its digits (59) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29183 + ... + 68621.

It is an arithmetic number, because the mean of its divisors is an integer number (140505000).

Almost surely, 2^1928645978 is an apocalyptic number.

1928645978 is a deficient number, since it is larger than the sum of its proper divisors (1443474022).

1928645978 is a wasteful number, since it uses less digits than its factorization.

1928645978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39954 (or 39947 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 59.

The square root of 1928645978 is about 43916.3520570641. The cubic root of 1928645978 is about 1244.7558384226.

The spelling of 1928645978 in words is "one billion, nine hundred twenty-eight million, six hundred forty-five thousand, nine hundred seventy-eight".