21055523236 has 24 divisors (see below), whose sum is σ = 41944601664. Its totient is φ = 9154574880.

The previous prime is 21055523221. The next prime is 21055523239. The reversal of 21055523236 is 63232555012.

It is not an unprimeable number, because it can be changed into a prime (21055523239) 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, 10401915 + ... + 10403938.

It is an arithmetic number, because the mean of its divisors is an integer number (1747691736).

Almost surely, 2^21055523236 is an apocalyptic number.

It is an amenable number.

21055523236 is a deficient number, since it is larger than the sum of its proper divisors (20889078428).

21055523236 is a wasteful number, since it uses less digits than its factorization.

21055523236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20805891 (or 20805889 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 34.

The spelling of 21055523236 in words is "twenty-one billion, fifty-five million, five hundred twenty-three thousand, two hundred thirty-six".