21960257539 has 4 divisors (see below), whose sum is σ = 23956644600. Its totient is φ = 19963870480.

The previous prime is 21960257533. The next prime is 21960257567. The reversal of 21960257539 is 93575206912.

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 21960257539 - 2⁷ = 21960257411 is a prime.

It is a super-2 number, since 2×21960257539² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21960257492 and 21960257501.

It is not an unprimeable number, because it can be changed into a prime (21960257533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 998193514 + ... + 998193535.

It is an arithmetic number, because the mean of its divisors is an integer number (5989161150).

Almost surely, 2^21960257539 is an apocalyptic number.

21960257539 is a deficient number, since it is larger than the sum of its proper divisors (1996387061).

21960257539 is a wasteful number, since it uses less digits than its factorization.

21960257539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1996387060.

The product of its (nonzero) digits is 1020600, while the sum is 49.

The spelling of 21960257539 in words is "twenty-one billion, nine hundred sixty million, two hundred fifty-seven thousand, five hundred thirty-nine".