21570727205651 has 8 divisors (see below), whose sum is σ = 23236519148304. Its totient is φ = 19905864582240.

The previous prime is 21570727205647. The next prime is 21570727205693. The reversal of 21570727205651 is 15650272707512.

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

It is not a de Polignac number, because 21570727205651 - 2² = 21570727205647 is a prime.

It is a super-2 number, since 2×21570727205651² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21570727205651.

It is not an unprimeable number, because it can be changed into a prime (21570727205611) 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, 232281596 + ... + 232374441.

It is an arithmetic number, because the mean of its divisors is an integer number (2904564893538).

Almost surely, 2^{21570727205651} is an apocalyptic number.

21570727205651 is a deficient number, since it is larger than the sum of its proper divisors (1665791942653).

21570727205651 is a wasteful number, since it uses less digits than its factorization.

21570727205651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 464659621.

The product of its (nonzero) digits is 2058000, while the sum is 50.

The spelling of 21570727205651 in words is "twenty-one trillion, five hundred seventy billion, seven hundred twenty-seven million, two hundred five thousand, six hundred fifty-one".