21260531513563 has 4 divisors (see below), whose sum is σ = 21261808362328. Its totient is φ = 21259254664800.

The previous prime is 21260531513519. The next prime is 21260531513593. The reversal of 21260531513563 is 36531513506212.

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

It is a cyclic number.

It is not a de Polignac number, because 21260531513563 - 2¹³ = 21260531505371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21260531513503) 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, 638399406 + ... + 638432707.

It is an arithmetic number, because the mean of its divisors is an integer number (5315452090582).

Almost surely, 2^{21260531513563} is an apocalyptic number.

21260531513563 is a deficient number, since it is larger than the sum of its proper divisors (1276848765).

21260531513563 is a wasteful number, since it uses less digits than its factorization.

21260531513563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1276848764.

The product of its (nonzero) digits is 486000, while the sum is 43.

The spelling of 21260531513563 in words is "twenty-one trillion, two hundred sixty billion, five hundred thirty-one million, five hundred thirteen thousand, five hundred sixty-three".