21480557857 has 16 divisors (see below), whose sum is σ = 23533148160. Its totient is φ = 19444770000.

The previous prime is 21480557797. The next prime is 21480557867. The reversal of 21480557857 is 75875508412.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21480557857 is a prime.

It is a super-2 number, since 2×21480557857² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21480557867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2962078 + ... + 2969320.

It is an arithmetic number, because the mean of its divisors is an integer number (1470821760).

Almost surely, 2^21480557857 is an apocalyptic number.

It is an amenable number.

21480557857 is a deficient number, since it is larger than the sum of its proper divisors (2052590303).

21480557857 is a wasteful number, since it uses less digits than its factorization.

21480557857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8364.

The product of its (nonzero) digits is 3136000, while the sum is 52.

The spelling of 21480557857 in words is "twenty-one billion, four hundred eighty million, five hundred fifty-seven thousand, eight hundred fifty-seven".