30505907861 has 12 divisors (see below), whose sum is σ = 36110618796. Its totient is φ = 25599361920.

The previous prime is 30505907827. The next prime is 30505907893. The reversal of 30505907861 is 16870950503.

It can be written as a sum of positive squares in 2 ways, for example, as 3386076100 + 27119831761 = 58190^2 + 164681^2 .

It is a de Polignac number, because none of the positive numbers 2^k-30505907861 is a prime.

It is a super-2 number, since 2×30505907861² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30508907861) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9695156 + ... + 9698301.

It is an arithmetic number, because the mean of its divisors is an integer number (3009218233).

Almost surely, 2^30505907861 is an apocalyptic number.

It is an amenable number.

30505907861 is a deficient number, since it is larger than the sum of its proper divisors (5604710935).

30505907861 is a wasteful number, since it uses less digits than its factorization.

30505907861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19393492 (or 19393481 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 44.

The spelling of 30505907861 in words is "thirty billion, five hundred five million, nine hundred seven thousand, eight hundred sixty-one".