21361429428 has 24 divisors (see below), whose sum is σ = 49845865440. Its totient is φ = 7120115040.

The previous prime is 21361429403. The next prime is 21361429471. The reversal of 21361429428 is 82492416312.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21361429428.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317583 + ... + 378921.

It is an arithmetic number, because the mean of its divisors is an integer number (2076911060).

Almost surely, 2^21361429428 is an apocalyptic number.

It is an amenable number.

21361429428 is an abundant number, since it is smaller than the sum of its proper divisors (28484436012).

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

21361429428 is a wasteful number, since it uses less digits than its factorization.

21361429428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90367 (or 90365 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The spelling of 21361429428 in words is "twenty-one billion, three hundred sixty-one million, four hundred twenty-nine thousand, four hundred twenty-eight".