4642135681 has 2 divisors, whose sum is σ = 4642135682. Its totient is φ = 4642135680.

The previous prime is 4642135679. The next prime is 4642135697. The reversal of 4642135681 is 1865312464.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4011322225 + 630813456 = 63335^2 + 25116^2 .

It is a cyclic number.

It is not a de Polignac number, because 4642135681 - 2¹ = 4642135679 is a prime.

It is a super-2 number, since 2×4642135681² = 43098847361626667522, which contains 22 as substring.

Together with 4642135679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (4642133681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2321067840 + 2321067841.

It is an arithmetic number, because the mean of its divisors is an integer number (2321067841).

Almost surely, 2^4642135681 is an apocalyptic number.

It is an amenable number.

4642135681 is a deficient number, since it is larger than the sum of its proper divisors (1).

4642135681 is an equidigital number, since it uses as much as digits as its factorization.

4642135681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 138240, while the sum is 40.

The square root of 4642135681 is about 68133.2200985687. The cubic root of 4642135681 is about 1668.1660435480.

The spelling of 4642135681 in words is "four billion, six hundred forty-two million, one hundred thirty-five thousand, six hundred eighty-one".