21642950026 has 4 divisors (see below), whose sum is σ = 32464425042. Its totient is φ = 10821475012.

The previous prime is 21642950023. The next prime is 21642950033. The reversal of 21642950026 is 62005924612.

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., 15537871801 + 6105078225 = 124651^2 + 78135^2 .

It is not an unprimeable number, because it can be changed into a prime (21642950023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5410737505 + ... + 5410737508.

Almost surely, 2^21642950026 is an apocalyptic number.

21642950026 is a deficient number, since it is larger than the sum of its proper divisors (10821475016).

21642950026 is a wasteful number, since it uses less digits than its factorization.

21642950026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10821475015.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21642950026 in words is "twenty-one billion, six hundred forty-two million, nine hundred fifty thousand, twenty-six".