1920657778 has 64 divisors (see below), whose sum is σ = 3264613632. Its totient is φ = 841800960.

The previous prime is 1920657749. The next prime is 1920657779. The reversal of 1920657778 is 8777560291.

It is not an unprimeable number, because it can be changed into a prime (1920657779) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6555000 + ... + 6555292.

It is an arithmetic number, because the mean of its divisors is an integer number (51009588).

Almost surely, 2^1920657778 is an apocalyptic number.

1920657778 is a deficient number, since it is larger than the sum of its proper divisors (1343955854).

1920657778 is a wasteful number, since it uses less digits than its factorization.

1920657778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499.

The product of its (nonzero) digits is 1481760, while the sum is 52.

The square root of 1920657778 is about 43825.3097878384. The cubic root of 1920657778 is about 1243.0349215359.

The spelling of 1920657778 in words is "one billion, nine hundred twenty million, six hundred fifty-seven thousand, seven hundred seventy-eight".