21539343807 has 24 divisors (see below), whose sum is σ = 32477608800. Its totient is φ = 13729940928.

The previous prime is 21539343773. The next prime is 21539343821. The reversal of 21539343807 is 70834393512.

21539343807 is a `hidden beast` number, since 2 + 1 + 539 + 34 + 3 + 80 + 7 = 666.

It is not a de Polignac number, because 21539343807 - 2⁶ = 21539343743 is a prime.

It is a super-2 number, since 2×21539343807² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21539343907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 558669 + ... + 595977.

It is an arithmetic number, because the mean of its divisors is an integer number (1353233700).

Almost surely, 2^21539343807 is an apocalyptic number.

21539343807 is a deficient number, since it is larger than the sum of its proper divisors (10938264993).

21539343807 is a wasteful number, since it uses less digits than its factorization.

21539343807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40127 (or 40124 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 21539343807 in words is "twenty-one billion, five hundred thirty-nine million, three hundred forty-three thousand, eight hundred seven".