21166346057 has 16 divisors (see below), whose sum is σ = 21561914880. Its totient is φ = 20774802048.

The previous prime is 21166346053. The next prime is 21166346081. The reversal of 21166346057 is 75064366112.

It is a cyclic number.

It is not a de Polignac number, because 21166346057 - 2² = 21166346053 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21166346051) 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, 9589448 + ... + 9591654.

It is an arithmetic number, because the mean of its divisors is an integer number (1347619680).

Almost surely, 2^21166346057 is an apocalyptic number.

It is an amenable number.

21166346057 is a deficient number, since it is larger than the sum of its proper divisors (395568823).

21166346057 is a wasteful number, since it uses less digits than its factorization.

21166346057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3040.

The product of its (nonzero) digits is 181440, while the sum is 41.

The spelling of 21166346057 in words is "twenty-one billion, one hundred sixty-six million, three hundred forty-six thousand, fifty-seven".