20421522464516 has 18 divisors (see below), whose sum is σ = 36109892151018. Its totient is φ = 10105495633920.

The previous prime is 20421522464509. The next prime is 20421522464579. The reversal of 20421522464516 is 61546422512402.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 12089882116 + 20409432582400 = 109954^2 + 4517680^2 .

It is a super-2 number, since 2×20421522464516² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 271265405 + ... + 271340676.

It is an arithmetic number, because the mean of its divisors is an integer number (2006105119501).

Almost surely, 2^{20421522464516} is an apocalyptic number.

It is an amenable number.

20421522464516 is a deficient number, since it is larger than the sum of its proper divisors (15688369686502).

20421522464516 is an equidigital number, since it uses as much as digits as its factorization.

20421522464516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542606279 (or 542606180 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 44.

Adding to 20421522464516 its reverse (61546422512402), we get a palindrome (81967944976918).

The spelling of 20421522464516 in words is "twenty trillion, four hundred twenty-one billion, five hundred twenty-two million, four hundred sixty-four thousand, five hundred sixteen".