21202254642 has 48 divisors (see below), whose sum is σ = 43629998976. Its totient is φ = 6868713600.

The previous prime is 21202254631. The next prime is 21202254643. The reversal of 21202254642 is 24645220212.

It is not an unprimeable number, because it can be changed into a prime (21202254643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2729428 + ... + 2737184.

It is an arithmetic number, because the mean of its divisors is an integer number (908958312).

Almost surely, 2^21202254642 is an apocalyptic number.

21202254642 is an abundant number, since it is smaller than the sum of its proper divisors (22427744334).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21202254642 is a wasteful number, since it uses less digits than its factorization.

21202254642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8115 (or 8074 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 21202254642 its reverse (24645220212), we get a palindrome (45847474854).

The spelling of 21202254642 in words is "twenty-one billion, two hundred two million, two hundred fifty-four thousand, six hundred forty-two".