20491390602648 has 72 divisors (see below), whose sum is σ = 64558335200580. Its totient is φ = 5854683028320.

The previous prime is 20491390602607. The next prime is 20491390602721. The reversal of 20491390602648 is 84620609319402.

20491390602648 is a `hidden beast` number, since 2 + 0 + 491 + 3 + 90 + 6 + 0 + 2 + 64 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×20491390602648² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20491390602594 and 20491390602603.

It is a congruent number.

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 17 ways as a sum of consecutive naturals, for example, 2904105118 + ... + 2904112173.

Almost surely, 2^{20491390602648} is an apocalyptic number.

20491390602648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20491390602648 is an abundant number, since it is smaller than the sum of its proper divisors (44066944597932).

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

20491390602648 is a wasteful number, since it uses less digits than its factorization.

20491390602648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5808217317 (or 5808217303 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 54.

The spelling of 20491390602648 in words is "twenty trillion, four hundred ninety-one billion, three hundred ninety million, six hundred two thousand, six hundred forty-eight".