21100042642 has 8 divisors (see below), whose sum is σ = 36171501696. Its totient is φ = 9042875412.

The previous prime is 21100042631. The next prime is 21100042669. The reversal of 21100042642 is 24624000112.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 753572938 + ... + 753572965.

It is an arithmetic number, because the mean of its divisors is an integer number (4521437712).

Almost surely, 2^21100042642 is an apocalyptic number.

21100042642 is a deficient number, since it is larger than the sum of its proper divisors (15071459054).

21100042642 is a wasteful number, since it uses less digits than its factorization.

21100042642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1507145912.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21100042642 its reverse (24624000112), we get a palindrome (45724042754).

The spelling of 21100042642 in words is "twenty-one billion, one hundred million, forty-two thousand, six hundred forty-two".