21057051123 has 6 divisors (see below), whose sum is σ = 30415740524. Its totient is φ = 14038034076.

The previous prime is 21057051121. The next prime is 21057051137. The reversal of 21057051123 is 32115075012.

21057051123 is a `hidden beast` number, since 21 + 0 + 570 + 51 + 1 + 23 = 666.

It is not a de Polignac number, because 21057051123 - 2¹ = 21057051121 is a prime.

It is a super-2 number, since 2×21057051123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21057051121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1169836165 + ... + 1169836182.

Almost surely, 2^21057051123 is an apocalyptic number.

21057051123 is a deficient number, since it is larger than the sum of its proper divisors (9358689401).

21057051123 is a wasteful number, since it uses less digits than its factorization.

21057051123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2339672353 (or 2339672350 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The spelling of 21057051123 in words is "twenty-one billion, fifty-seven million, fifty-one thousand, one hundred twenty-three".