21361290560 has 28 divisors (see below), whose sum is σ = 50866573908. Its totient is φ = 8544516096.

The previous prime is 21361290539. The next prime is 21361290571. The reversal of 21361290560 is 6509216312.

It can be written as a sum of positive squares in 2 ways, for example, as 13580639296 + 7780651264 = 116536^2 + 88208^2 .

It is a super-2 number, since 2×21361290560² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21361290560.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33376697 + ... + 33377336.

Almost surely, 2^21361290560 is an apocalyptic number.

21361290560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21361290560 is an abundant number, since it is smaller than the sum of its proper divisors (29505283348).

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

21361290560 is an equidigital number, since it uses as much as digits as its factorization.

21361290560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66754050 (or 66754040 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The spelling of 21361290560 in words is "twenty-one billion, three hundred sixty-one million, two hundred ninety thousand, five hundred sixty".