1939775681 has 4 divisors (see below), whose sum is σ = 1981047552. Its totient is φ = 1898503812.

The previous prime is 1939775671. The next prime is 1939775689. The reversal of 1939775681 is 1865779391.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1939775681 - 2²² = 1935581377 is a prime.

It is a super-2 number, since 2×1939775681² = 7525459385198027522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1939775689) 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, 20635865 + ... + 20635958.

It is an arithmetic number, because the mean of its divisors is an integer number (495261888).

Almost surely, 2^1939775681 is an apocalyptic number.

It is an amenable number.

1939775681 is a deficient number, since it is larger than the sum of its proper divisors (41271871).

1939775681 is an equidigital number, since it uses as much as digits as its factorization.

1939775681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41271870.

The product of its digits is 2857680, while the sum is 56.

The square root of 1939775681 is about 44042.8845672034. The cubic root of 1939775681 is about 1247.1456323093.

The spelling of 1939775681 in words is "one billion, nine hundred thirty-nine million, seven hundred seventy-five thousand, six hundred eighty-one".