642215266681 has 8 divisors (see below), whose sum is σ = 645544715904. Its totient is φ = 638886519600.

The previous prime is 642215266657. The next prime is 642215266703. The reversal of 642215266681 is 186662512246.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642215266681 - 2³⁹ = 92459452793 is a prime.

It is a super-2 number, since 2×642215266681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642215206681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1710886 + ... + 2052208.

It is an arithmetic number, because the mean of its divisors is an integer number (80693089488).

Almost surely, 2^642215266681 is an apocalyptic number.

It is an amenable number.

642215266681 is a deficient number, since it is larger than the sum of its proper divisors (3329449223).

642215266681 is a wasteful number, since it uses less digits than its factorization.

642215266681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351071.

The product of its digits is 1658880, while the sum is 49.

The spelling of 642215266681 in words is "six hundred forty-two billion, two hundred fifteen million, two hundred sixty-six thousand, six hundred eighty-one".