21221927541 has 24 divisors (see below), whose sum is σ = 30921606144. Its totient is φ = 14024818080.

The previous prime is 21221927539. The next prime is 21221927561. The reversal of 21221927541 is 14572912212.

It is a happy number.

21221927541 is a `hidden beast` number, since 2 + 1 + 2 + 21 + 92 + 7 + 541 = 666.

It is not a de Polignac number, because 21221927541 - 2¹ = 21221927539 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221927496 and 21221927505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221927501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 591580 + ... + 626426.

It is an arithmetic number, because the mean of its divisors is an integer number (1288400256).

Almost surely, 2^21221927541 is an apocalyptic number.

It is an amenable number.

21221927541 is a deficient number, since it is larger than the sum of its proper divisors (9699678603).

21221927541 is a wasteful number, since it uses less digits than its factorization.

21221927541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35441 (or 35438 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The spelling of 21221927541 in words is "twenty-one billion, two hundred twenty-one million, nine hundred twenty-seven thousand, five hundred forty-one".