20305406646 has 48 divisors (see below), whose sum is σ = 52490173680. Its totient is φ = 5801544000.

The previous prime is 20305406621. The next prime is 20305406651. The reversal of 20305406646 is 64660450302.

20305406646 is a `hidden beast` number, since 2 + 0 + 3 + 0 + 5 + 4 + 0 + 6 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20305406646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3834355 + ... + 3839646.

It is an arithmetic number, because the mean of its divisors is an integer number (1093545285).

Almost surely, 2^20305406646 is an apocalyptic number.

20305406646 is an abundant number, since it is smaller than the sum of its proper divisors (32184767034).

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

20305406646 is a wasteful number, since it uses less digits than its factorization.

20305406646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7674026 (or 7674013 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

Adding to 20305406646 its reverse (64660450302), we get a palindrome (84965856948).

The spelling of 20305406646 in words is "twenty billion, three hundred five million, four hundred six thousand, six hundred forty-six".