21522566461 has 8 divisors (see below), whose sum is σ = 23482669824. Its totient is φ = 19563047520.

The previous prime is 21522566459. The next prime is 21522566501. The reversal of 21522566461 is 16466522512.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21522566461 - 2¹ = 21522566459 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522566561) 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, 67245 + ... + 218098.

It is an arithmetic number, because the mean of its divisors is an integer number (2935333728).

Almost surely, 2^21522566461 is an apocalyptic number.

It is an amenable number.

21522566461 is a deficient number, since it is larger than the sum of its proper divisors (1960103363).

21522566461 is a wasteful number, since it uses less digits than its factorization.

21522566461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292211.

The product of its digits is 172800, while the sum is 40.

The spelling of 21522566461 in words is "twenty-one billion, five hundred twenty-two million, five hundred sixty-six thousand, four hundred sixty-one".