21602360445361 has 4 divisors (see below), whose sum is σ = 21620652030324. Its totient is φ = 21584068860400.

The previous prime is 21602360445359. The next prime is 21602360445373. The reversal of 21602360445361 is 16354406320612.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20104184445361 + 1498176000000 = 4483769^2 + 1224000^2 .

It is a cyclic number.

It is not a de Polignac number, because 21602360445361 - 2¹ = 21602360445359 is a prime.

It is a super-2 number, since 2×21602360445361² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21602360445661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9145790710 + ... + 9145793071.

It is an arithmetic number, because the mean of its divisors is an integer number (5405163007581).

Almost surely, 2^{21602360445361} is an apocalyptic number.

It is an amenable number.

21602360445361 is a deficient number, since it is larger than the sum of its proper divisors (18291584963).

21602360445361 is a wasteful number, since it uses less digits than its factorization.

21602360445361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18291584962.

The product of its (nonzero) digits is 622080, while the sum is 43.

Adding to 21602360445361 its reverse (16354406320612), we get a palindrome (37956766765973).

The spelling of 21602360445361 in words is "twenty-one trillion, six hundred two billion, three hundred sixty million, four hundred forty-five thousand, three hundred sixty-one".