21306524450 has 12 divisors (see below), whose sum is σ = 39630135570. Its totient is φ = 8522609760.

The previous prime is 21306524441. The next prime is 21306524453. The reversal of 21306524450 is 5442560312.

It can be written as a sum of positive squares in 3 ways, for example, as 20210318569 + 1096205881 = 142163^2 + 33109^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21306524453) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 213065195 + ... + 213065294.

Almost surely, 2^21306524450 is an apocalyptic number.

21306524450 is a deficient number, since it is larger than the sum of its proper divisors (18323611120).

21306524450 is a wasteful number, since it uses less digits than its factorization.

21306524450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426130501 (or 426130496 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

The spelling of 21306524450 in words is "twenty-one billion, three hundred six million, five hundred twenty-four thousand, four hundred fifty".