21670577281 has 4 divisors (see below), whose sum is σ = 22811134000. Its totient is φ = 20530020564.

The previous prime is 21670577219. The next prime is 21670577293. The reversal of 21670577281 is 18277507612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21670577281 - 2¹¹ = 21670575233 is a prime.

It is a super-2 number, since 2×21670577281² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21670577081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 570278331 + ... + 570278368.

It is an arithmetic number, because the mean of its divisors is an integer number (5702783500).

Almost surely, 2^21670577281 is an apocalyptic number.

It is an amenable number.

21670577281 is a deficient number, since it is larger than the sum of its proper divisors (1140556719).

21670577281 is a wasteful number, since it uses less digits than its factorization.

21670577281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140556718.

The product of its (nonzero) digits is 329280, while the sum is 46.

The spelling of 21670577281 in words is "twenty-one billion, six hundred seventy million, five hundred seventy-seven thousand, two hundred eighty-one".