21111166401 has 8 divisors (see below), whose sum is σ = 30313469760. Its totient is φ = 12991486992.

The previous prime is 21111166387. The next prime is 21111166403. The reversal of 21111166401 is 10466111112.

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

It is not a de Polignac number, because 21111166401 - 2¹³ = 21111158209 is a prime.

It is a super-2 number, since 2×21111166401² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21111166403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 270655941 + ... + 270656018.

It is an arithmetic number, because the mean of its divisors is an integer number (3789183720).

Almost surely, 2^21111166401 is an apocalyptic number.

It is an amenable number.

21111166401 is a deficient number, since it is larger than the sum of its proper divisors (9202303359).

21111166401 is a wasteful number, since it uses less digits than its factorization.

21111166401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541311975.

The product of its (nonzero) digits is 288, while the sum is 24.

Adding to 21111166401 its reverse (10466111112), we get a palindrome (31577277513).

The spelling of 21111166401 in words is "twenty-one billion, one hundred eleven million, one hundred sixty-six thousand, four hundred one".