1920993985 has 4 divisors (see below), whose sum is σ = 2305192788. Its totient is φ = 1536795184.

The previous prime is 1920993953. The next prime is 1920994001. The reversal of 1920993985 is 5893990291.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5893990291 = 7 ⋅841998613.

It can be written as a sum of positive squares in 2 ways, for example, as 1305160129 + 615833856 = 36127^2 + 24816^2 .

It is a cyclic number.

It is not a de Polignac number, because 1920993985 - 2⁵ = 1920993953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 192099394 + ... + 192099403.

It is an arithmetic number, because the mean of its divisors is an integer number (576298197).

Almost surely, 2^1920993985 is an apocalyptic number.

It is an amenable number.

1920993985 is a deficient number, since it is larger than the sum of its proper divisors (384198803).

1920993985 is an equidigital number, since it uses as much as digits as its factorization.

1920993985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384198802.

The product of its (nonzero) digits is 1574640, while the sum is 55.

The square root of 1920993985 is about 43829.1453829527. The cubic root of 1920993985 is about 1243.1074474979.

The spelling of 1920993985 in words is "one billion, nine hundred twenty million, nine hundred ninety-three thousand, nine hundred eighty-five".