21432837861 has 6 divisors (see below), whose sum is σ = 30958543590. Its totient is φ = 14288558568.

The previous prime is 21432837859. The next prime is 21432837871. The reversal of 21432837861 is 16873823412.

21432837861 is a `hidden beast` number, since 214 + 3 + 2 + 8 + 378 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21367130625 + 65707236 = 146175^2 + 8106^2 .

It is not a de Polignac number, because 21432837861 - 2¹ = 21432837859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432837821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1190713206 + ... + 1190713223.

It is an arithmetic number, because the mean of its divisors is an integer number (5159757265).

Almost surely, 2^21432837861 is an apocalyptic number.

It is an amenable number.

21432837861 is a deficient number, since it is larger than the sum of its proper divisors (9525705729).

21432837861 is a wasteful number, since it uses less digits than its factorization.

21432837861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2381426435 (or 2381426432 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 21432837861 in words is "twenty-one billion, four hundred thirty-two million, eight hundred thirty-seven thousand, eight hundred sixty-one".