21689068428 has 36 divisors (see below), whose sum is σ = 54840823128. Its totient is φ = 7227622080.

The previous prime is 21689068409. The next prime is 21689068451. The reversal of 21689068428 is 82486098612.

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

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, 44200 + ... + 212912.

It is an arithmetic number, because the mean of its divisors is an integer number (1523356198).

Almost surely, 2^21689068428 is an apocalyptic number.

It is an amenable number.

21689068428 is an abundant number, since it is smaller than the sum of its proper divisors (33151754700).

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

21689068428 is a wasteful number, since it uses less digits than its factorization.

21689068428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172294 (or 172289 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 54.

The spelling of 21689068428 in words is "twenty-one billion, six hundred eighty-nine million, sixty-eight thousand, four hundred twenty-eight".