1920643765 has 16 divisors (see below), whose sum is σ = 2462747760. Its totient is φ = 1432857600.

The previous prime is 1920643661. The next prime is 1920643771. The reversal of 1920643765 is 5673460291.

It can be written as a sum of positive squares in 8 ways, for example, as 27436644 + 1893207121 = 5238^2 + 43511^2 .

It is not a de Polignac number, because 1920643765 - 2¹³ = 1920635573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94386 + ... + 112915.

It is an arithmetic number, because the mean of its divisors is an integer number (153921735).

Almost surely, 2^1920643765 is an apocalyptic number.

It is an amenable number.

1920643765 is a deficient number, since it is larger than the sum of its proper divisors (542103995).

1920643765 is a wasteful number, since it uses less digits than its factorization.

1920643765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207432.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 1920643765 is about 43825.1499141760. The cubic root of 1920643765 is about 1243.0318984933.

The spelling of 1920643765 in words is "one billion, nine hundred twenty million, six hundred forty-three thousand, seven hundred sixty-five".