21342575655 has 32 divisors (see below), whose sum is σ = 37960689600. Its totient is φ = 11377207296.

The previous prime is 21342575651. The next prime is 21342575677. The reversal of 21342575655 is 55657524312.

It is a happy number.

21342575655 is a `hidden beast` number, since 2 + 1 + 34 + 2 + 57 + 565 + 5 = 666.

It is not a de Polignac number, because 21342575655 - 2² = 21342575651 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21342575655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342575651) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 250287 + ... + 324543.

It is an arithmetic number, because the mean of its divisors is an integer number (1186271550).

Almost surely, 2^21342575655 is an apocalyptic number.

21342575655 is a deficient number, since it is larger than the sum of its proper divisors (16618113945).

21342575655 is a wasteful number, since it uses less digits than its factorization.

21342575655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76400 (or 76394 counting only the distinct ones).

The product of its digits is 1260000, while the sum is 45.

The spelling of 21342575655 in words is "twenty-one billion, three hundred forty-two million, five hundred seventy-five thousand, six hundred fifty-five".