21401596959563 has 4 divisors (see below), whose sum is σ = 22527996799560. Its totient is φ = 20275197119568.

The previous prime is 21401596959551. The next prime is 21401596959571. The reversal of 21401596959563 is 36595969510412.

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

It is not a de Polignac number, because 21401596959563 - 2⁸ = 21401596959307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21401596959563.

It is not an unprimeable number, because it can be changed into a prime (21401596959583) 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, 563199919970 + ... + 563199920007.

It is an arithmetic number, because the mean of its divisors is an integer number (5631999199890).

Almost surely, 2^{21401596959563} is an apocalyptic number.

21401596959563 is a deficient number, since it is larger than the sum of its proper divisors (1126399839997).

21401596959563 is a wasteful number, since it uses less digits than its factorization.

21401596959563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126399839996.

The product of its (nonzero) digits is 78732000, while the sum is 65.

The spelling of 21401596959563 in words is "twenty-one trillion, four hundred one billion, five hundred ninety-six million, nine hundred fifty-nine thousand, five hundred sixty-three".