21705046764 has 24 divisors (see below), whose sum is σ = 51358422528. Its totient is φ = 7133113680.

The previous prime is 21705046751. The next prime is 21705046861. The reversal of 21705046764 is 46764050712.

It is a super-2 number, since 2×21705046764² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 12736852 + ... + 12738555.

It is an arithmetic number, because the mean of its divisors is an integer number (2139934272).

Almost surely, 2^21705046764 is an apocalyptic number.

It is an amenable number.

21705046764 is an abundant number, since it is smaller than the sum of its proper divisors (29653375764).

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

21705046764 is a wasteful number, since it uses less digits than its factorization.

21705046764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25475485 (or 25475483 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 42.

The spelling of 21705046764 in words is "twenty-one billion, seven hundred five million, forty-six thousand, seven hundred sixty-four".