21236623434 has 24 divisors (see below), whose sum is σ = 49552121892. Its totient is φ = 6534345600.

The previous prime is 21236623393. The next prime is 21236623543. The reversal of 21236623434 is 43432663212.

21236623434 is a `hidden beast` number, since 2 + 1 + 23 + 6 + 623 + 4 + 3 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20974280625 + 262342809 = 144825^2 + 16197^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45377167 + ... + 45377634.

Almost surely, 2^21236623434 is an apocalyptic number.

21236623434 is an abundant number, since it is smaller than the sum of its proper divisors (28315498458).

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

21236623434 is a wasteful number, since it uses less digits than its factorization.

21236623434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90754822 (or 90754819 counting only the distinct ones).

The product of its digits is 124416, while the sum is 36.

The spelling of 21236623434 in words is "twenty-one billion, two hundred thirty-six million, six hundred twenty-three thousand, four hundred thirty-four".