21571352655 has 8 divisors (see below), whose sum is σ = 34514164272. Its totient is φ = 11504721408.

The previous prime is 21571352653. The next prime is 21571352753. The reversal of 21571352655 is 55625317512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21571352655 - 2¹ = 21571352653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21571352653) 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, 719045074 + ... + 719045103.

It is an arithmetic number, because the mean of its divisors is an integer number (4314270534).

Almost surely, 2^21571352655 is an apocalyptic number.

21571352655 is a deficient number, since it is larger than the sum of its proper divisors (12942811617).

21571352655 is a wasteful number, since it uses less digits than its factorization.

21571352655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438090185.

The product of its digits is 315000, while the sum is 42.

The spelling of 21571352655 in words is "twenty-one billion, five hundred seventy-one million, three hundred fifty-two thousand, six hundred fifty-five".