21621266532346 has 16 divisors (see below), whose sum is σ = 34929506722824. Its totient is φ = 9978233120064.

The previous prime is 21621266532337. The next prime is 21621266532347. The reversal of 21621266532346 is 64323566212612.

It can be written as a sum of positive squares in 4 ways, for example, as 8712975650625 + 12908290881721 = 2951775^2 + 3592811^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21621266532346.

It is not an unprimeable number, because it can be changed into a prime (21621266532347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33548485 + ... + 34186888.

Almost surely, 2^{21621266532346} is an apocalyptic number.

21621266532346 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21621266532346 is a deficient number, since it is larger than the sum of its proper divisors (13308240190478).

21621266532346 is a wasteful number, since it uses less digits than its factorization.

21621266532346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67747665.

The product of its digits is 3732480, while the sum is 49.

The spelling of 21621266532346 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred sixty-six million, five hundred thirty-two thousand, three hundred forty-six".