21117432436 has 12 divisors (see below), whose sum is σ = 39129360228. Its totient is φ = 9937615232.

The previous prime is 21117432379. The next prime is 21117432439. The reversal of 21117432436 is 63423471112.

It can be written as a sum of positive squares in 2 ways, for example, as 15057744100 + 6059688336 = 122710^2 + 77844^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117432439) 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, 155275171 + ... + 155275306.

It is an arithmetic number, because the mean of its divisors is an integer number (3260780019).

Almost surely, 2^21117432436 is an apocalyptic number.

It is an amenable number.

21117432436 is a deficient number, since it is larger than the sum of its proper divisors (18011927792).

21117432436 is a wasteful number, since it uses less digits than its factorization.

21117432436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310550498 (or 310550496 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The spelling of 21117432436 in words is "twenty-one billion, one hundred seventeen million, four hundred thirty-two thousand, four hundred thirty-six".