642837487373321 has 2 divisors, whose sum is σ = 642837487373322. Its totient is φ = 642837487373320.

The previous prime is 642837487373317. The next prime is 642837487373339. The reversal of 642837487373321 is 123373784738246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 456320560678921 + 186516926694400 = 21361661^2 + 13657120^2 .

It is a cyclic number.

It is not a de Polignac number, because 642837487373321 - 2² = 642837487373317 is a prime.

It is a super-2 number, since 2×642837487373321² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (642837487373371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321418743686660 + 321418743686661.

It is an arithmetic number, because the mean of its divisors is an integer number (321418743686661).

Almost surely, 2^{642837487373321} is an apocalyptic number.

It is an amenable number.

642837487373321 is a deficient number, since it is larger than the sum of its proper divisors (1).

642837487373321 is an equidigital number, since it uses as much as digits as its factorization.

642837487373321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 682795008, while the sum is 68.

The spelling of 642837487373321 in words is "six hundred forty-two trillion, eight hundred thirty-seven billion, four hundred eighty-seven million, three hundred seventy-three thousand, three hundred twenty-one".