21042602766 has 64 divisors (see below), whose sum is σ = 47735020800. Its totient is φ = 6869367648.

The previous prime is 21042602759. The next prime is 21042602783. The reversal of 21042602766 is 66720624012.

21042602766 is a `hidden beast` number, since 2 + 1 + 0 + 42 + 602 + 7 + 6 + 6 = 666.

21042602766 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21042602766² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21042602766.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 609105 + ... + 642723.

It is an arithmetic number, because the mean of its divisors is an integer number (745859700).

Almost surely, 2^21042602766 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21042602766, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23867510400).

21042602766 is an abundant number, since it is smaller than the sum of its proper divisors (26692418034).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21042602766 is a wasteful number, since it uses less digits than its factorization.

21042602766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33870 (or 33864 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The spelling of 21042602766 in words is "twenty-one billion, forty-two million, six hundred two thousand, seven hundred sixty-six".