642428266682 has 4 divisors (see below), whose sum is σ = 963642400026. Its totient is φ = 321214133340.

The previous prime is 642428266657. The next prime is 642428266691. The reversal of 642428266682 is 286662824246.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 615626975161 + 26801291521 = 784619^2 + 163711^2 .

It is a super-2 number, since 2×642428266682² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160607066669 + ... + 160607066672.

Almost surely, 2^642428266682 is an apocalyptic number.

642428266682 is a deficient number, since it is larger than the sum of its proper divisors (321214133344).

642428266682 is a wasteful number, since it uses less digits than its factorization.

642428266682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321214133343.

The product of its digits is 21233664, while the sum is 56.

The spelling of 642428266682 in words is "six hundred forty-two billion, four hundred twenty-eight million, two hundred sixty-six thousand, six hundred eighty-two".