21255555452 has 12 divisors (see below), whose sum is σ = 38479885080. Its totient is φ = 10261302576.

The previous prime is 21255555403. The next prime is 21255555487. The reversal of 21255555452 is 25455555212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91618658 + ... + 91618889.

It is an arithmetic number, because the mean of its divisors is an integer number (3206657090).

Almost surely, 2^21255555452 is an apocalyptic number.

It is an amenable number.

21255555452 is a deficient number, since it is larger than the sum of its proper divisors (17224329628).

21255555452 is a wasteful number, since it uses less digits than its factorization.

21255555452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183237580 (or 183237578 counting only the distinct ones).

The product of its digits is 500000, while the sum is 41.

The spelling of 21255555452 in words is "twenty-one billion, two hundred fifty-five million, five hundred fifty-five thousand, four hundred fifty-two".