21928129990 has 16 divisors (see below), whose sum is σ = 42506836848. Its totient is φ = 8096540256.

The previous prime is 21928129981. The next prime is 21928129997. The reversal of 21928129990 is 9992182912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21928129997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84338832 + ... + 84339091.

It is an arithmetic number, because the mean of its divisors is an integer number (2656677303).

Almost surely, 2^21928129990 is an apocalyptic number.

21928129990 is a deficient number, since it is larger than the sum of its proper divisors (20578706858).

21928129990 is a wasteful number, since it uses less digits than its factorization.

21928129990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168677943.

The product of its (nonzero) digits is 419904, while the sum is 52.

The spelling of 21928129990 in words is "twenty-one billion, nine hundred twenty-eight million, one hundred twenty-nine thousand, nine hundred ninety".