642491329547 has 4 divisors (see below), whose sum is σ = 642809869656. Its totient is φ = 642172789440.

The previous prime is 642491329537. The next prime is 642491329577. The reversal of 642491329547 is 745923194246.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 642491329547 - 2⁶ = 642491329483 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642491329492 and 642491329501.

It is not an unprimeable number, because it can be changed into a prime (642491329537) 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, 159267029 + ... + 159271062.

It is an arithmetic number, because the mean of its divisors is an integer number (160702467414).

Almost surely, 2^642491329547 is an apocalyptic number.

642491329547 is a deficient number, since it is larger than the sum of its proper divisors (318540109).

642491329547 is a wasteful number, since it uses less digits than its factorization.

642491329547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318540108.

The product of its digits is 13063680, while the sum is 56.

The spelling of 642491329547 in words is "six hundred forty-two billion, four hundred ninety-one million, three hundred twenty-nine thousand, five hundred forty-seven".