642231111621 has 32 divisors (see below), whose sum is σ = 962856373248. Its totient is φ = 377403949440.

The previous prime is 642231111589. The next prime is 642231111631. The reversal of 642231111621 is 126111132246.

It is not a de Polignac number, because 642231111621 - 2⁵ = 642231111589 is a prime.

It is a super-2 number, since 2×642231111621² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642231111631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1457401 + ... + 1846206.

It is an arithmetic number, because the mean of its divisors is an integer number (30089261664).

Almost surely, 2^642231111621 is an apocalyptic number.

It is an amenable number.

642231111621 is a deficient number, since it is larger than the sum of its proper divisors (320625261627).

642231111621 is a wasteful number, since it uses less digits than its factorization.

642231111621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3303801.

The product of its digits is 3456, while the sum is 30.

Adding to 642231111621 its reverse (126111132246), we get a palindrome (768342243867).

The spelling of 642231111621 in words is "six hundred forty-two billion, two hundred thirty-one million, one hundred eleven thousand, six hundred twenty-one".