21570656460661 has 96 divisors (see below), whose sum is σ = 28236045312000. Its totient is φ = 16282806986880.

The previous prime is 21570656460659. The next prime is 21570656460679. The reversal of 21570656460661 is 16606465607512.

It is a happy number.

It is not a de Polignac number, because 21570656460661 - 2¹ = 21570656460659 is a prime.

It is a super-2 number, since 2×21570656460661² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21570656460601) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5262417190 + ... + 5262421288.

It is an arithmetic number, because the mean of its divisors is an integer number (294125472000).

Almost surely, 2^{21570656460661} is an apocalyptic number.

It is an amenable number.

21570656460661 is a deficient number, since it is larger than the sum of its proper divisors (6665388851339).

21570656460661 is a wasteful number, since it uses less digits than its factorization.

21570656460661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5247 (or 5240 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 55.

The spelling of 21570656460661 in words is "twenty-one trillion, five hundred seventy billion, six hundred fifty-six million, four hundred sixty thousand, six hundred sixty-one".