1942540681 has 4 divisors (see below), whose sum is σ = 1989919764. Its totient is φ = 1895161600.

The previous prime is 1942540661. The next prime is 1942540697. The reversal of 1942540681 is 1860452491.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1860452491 = 43 ⋅43266337.

It can be written as a sum of positive squares in 2 ways, for example, as 227255625 + 1715285056 = 15075^2 + 41416^2 .

It is a cyclic number.

It is not a de Polignac number, because 1942540681 - 2²⁵ = 1908986249 is a prime.

It is a super-2 number, since 2×1942540681² = 7546928594679887522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1942540661) 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, 23689480 + ... + 23689561.

It is an arithmetic number, because the mean of its divisors is an integer number (497479941).

Almost surely, 2^1942540681 is an apocalyptic number.

It is an amenable number.

1942540681 is a deficient number, since it is larger than the sum of its proper divisors (47379083).

1942540681 is an equidigital number, since it uses as much as digits as its factorization.

1942540681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47379082.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 1942540681 is about 44074.2632496563. The cubic root of 1942540681 is about 1247.7379208142.

It can be divided in two parts, 19425 and 40681, that added together give a palindrome (60106).

The spelling of 1942540681 in words is "one billion, nine hundred forty-two million, five hundred forty thousand, six hundred eighty-one".