21243654526 has 4 divisors (see below), whose sum is σ = 31865481792. Its totient is φ = 10621827262.

The previous prime is 21243654521. The next prime is 21243654541. The reversal of 21243654526 is 62545634212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243654521) 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 as a sum of consecutive naturals, namely, 5310913630 + ... + 5310913633.

It is an arithmetic number, because the mean of its divisors is an integer number (7966370448).

Almost surely, 2^21243654526 is an apocalyptic number.

21243654526 is a deficient number, since it is larger than the sum of its proper divisors (10621827266).

21243654526 is a wasteful number, since it uses less digits than its factorization.

21243654526 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10621827265.

The product of its digits is 345600, while the sum is 40.

The spelling of 21243654526 in words is "twenty-one billion, two hundred forty-three million, six hundred fifty-four thousand, five hundred twenty-six".