642220817819 has 24 divisors (see below), whose sum is σ = 772415800800. Its totient is φ = 523007008128.

The previous prime is 642220817807. The next prime is 642220817857. The reversal of 642220817819 is 918718022246.

It is not a de Polignac number, because 642220817819 - 2⁴ = 642220817803 is a prime.

It is a super-2 number, since 2×642220817819² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642220817419) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30242 + ... + 1133735.

It is an arithmetic number, because the mean of its divisors is an integer number (32183991700).

Almost surely, 2^642220817819 is an apocalyptic number.

642220817819 is a deficient number, since it is larger than the sum of its proper divisors (130194982981).

642220817819 is a wasteful number, since it uses less digits than its factorization.

642220817819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164179 (or 1164156 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 50.

The spelling of 642220817819 in words is "six hundred forty-two billion, two hundred twenty million, eight hundred seventeen thousand, eight hundred nineteen".