21163663045261 has 8 divisors (see below), whose sum is σ = 23091815779200. Its totient is φ = 19236207539040.

The previous prime is 21163663045249. The next prime is 21163663045321. The reversal of 21163663045261 is 16254036636112.

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 21163663045261 - 2¹⁵ = 21163663012493 is a prime.

It is a super-2 number, since 2×21163663045261² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21163663745261) 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, 174243456 + ... + 174364873.

It is an arithmetic number, because the mean of its divisors is an integer number (2886476972400).

Almost surely, 2^{21163663045261} is an apocalyptic number.

It is an amenable number.

21163663045261 is a deficient number, since it is larger than the sum of its proper divisors (1928152733939).

21163663045261 is a wasteful number, since it uses less digits than its factorization.

21163663045261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348613859.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 21163663045261 in words is "twenty-one trillion, one hundred sixty-three billion, six hundred sixty-three million, forty-five thousand, two hundred sixty-one".