21436415136 has 36 divisors (see below), whose sum is σ = 60959806362. Its totient is φ = 7145471616.

The previous prime is 21436415129. The next prime is 21436415159. The reversal of 21436415136 is 63151463412.

21436415136 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 641 + 5 + 1 + 3 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18665024400 + 2771390736 = 136620^2 + 52644^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21436415136.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37215711 + ... + 37216286.

Almost surely, 2^21436415136 is an apocalyptic number.

It is an amenable number.

21436415136 is an abundant number, since it is smaller than the sum of its proper divisors (39523391226).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21436415136 is a wasteful number, since it uses less digits than its factorization.

21436415136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74432013 (or 74432002 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

Adding to 21436415136 its reverse (63151463412), we get a palindrome (84587878548).

The spelling of 21436415136 in words is "twenty-one billion, four hundred thirty-six million, four hundred fifteen thousand, one hundred thirty-six".