21241266557 has 16 divisors (see below), whose sum is σ = 25147441152. Its totient is φ = 17557173360.

The previous prime is 21241266551. The next prime is 21241266577. The reversal of 21241266557 is 75566214212.

It is a cyclic number.

It is not a de Polignac number, because 21241266557 - 2⁶ = 21241266493 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 (21241266551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111533 + ... + 234354.

It is an arithmetic number, because the mean of its divisors is an integer number (1571715072).

Almost surely, 2^21241266557 is an apocalyptic number.

It is an amenable number.

21241266557 is a deficient number, since it is larger than the sum of its proper divisors (3906174595).

21241266557 is a wasteful number, since it uses less digits than its factorization.

21241266557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346208.

The product of its digits is 201600, while the sum is 41.

The spelling of 21241266557 in words is "twenty-one billion, two hundred forty-one million, two hundred sixty-six thousand, five hundred fifty-seven".