21705557030 has 16 divisors (see below), whose sum is σ = 40022930304. Its totient is φ = 8470461120.

The previous prime is 21705557017. The next prime is 21705557047. The reversal of 21705557030 is 3075550712.

It is a super-2 number, since 2×21705557030² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26469782 + ... + 26470601.

It is an arithmetic number, because the mean of its divisors is an integer number (2501433144).

Almost surely, 2^21705557030 is an apocalyptic number.

21705557030 is a deficient number, since it is larger than the sum of its proper divisors (18317373274).

21705557030 is a wasteful number, since it uses less digits than its factorization.

21705557030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52940431.

The product of its (nonzero) digits is 36750, while the sum is 35.

The spelling of 21705557030 in words is "twenty-one billion, seven hundred five million, five hundred fifty-seven thousand, thirty".