21225752661 has 8 divisors (see below), whose sum is σ = 28305198144. Its totient is φ = 14148404480.

The previous prime is 21225752633. The next prime is 21225752711. The reversal of 21225752661 is 16625752212.

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 21225752661 - 2²⁶ = 21158643797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225752461) 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, 500556 + ... + 541301.

It is an arithmetic number, because the mean of its divisors is an integer number (3538149768).

Almost surely, 2^21225752661 is an apocalyptic number.

It is an amenable number.

21225752661 is a deficient number, since it is larger than the sum of its proper divisors (7079445483).

21225752661 is a wasteful number, since it uses less digits than its factorization.

21225752661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048651.

The product of its digits is 100800, while the sum is 39.

The spelling of 21225752661 in words is "twenty-one billion, two hundred twenty-five million, seven hundred fifty-two thousand, six hundred sixty-one".