642721424137 has 16 divisors (see below), whose sum is σ = 711897723712. Its totient is φ = 576411007680.

The previous prime is 642721424123. The next prime is 642721424161. The reversal of 642721424137 is 731424127246.

It is a cyclic number.

It is not a de Polignac number, because 642721424137 - 2¹¹ = 642721422089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642721424093 and 642721424102.

It is not an unprimeable number, because it can be changed into a prime (642721424197) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 634503 + ... + 1299244.

It is an arithmetic number, because the mean of its divisors is an integer number (44493607732).

Almost surely, 2^642721424137 is an apocalyptic number.

It is an amenable number.

642721424137 is a deficient number, since it is larger than the sum of its proper divisors (69176299575).

642721424137 is a wasteful number, since it uses less digits than its factorization.

642721424137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1934488.

The product of its digits is 451584, while the sum is 43.

The spelling of 642721424137 in words is "six hundred forty-two billion, seven hundred twenty-one million, four hundred twenty-four thousand, one hundred thirty-seven".