9908780377661 has 16 divisors (see below), whose sum is σ = 11442070886400. Its totient is φ = 8486202510000.

The previous prime is 9908780377637. The next prime is 9908780377663. The reversal of 9908780377661 is 1667730878099.

It is a cyclic number.

It is not a de Polignac number, because 9908780377661 - 2⁶ = 9908780377597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9908780377663) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 132393965 + ... + 132468786.

It is an arithmetic number, because the mean of its divisors is an integer number (715129430400).

Almost surely, 2^{9908780377661} is an apocalyptic number.

It is an amenable number.

9908780377661 is a deficient number, since it is larger than the sum of its proper divisors (1533290508739).

9908780377661 is a wasteful number, since it uses less digits than its factorization.

9908780377661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264862960.

The product of its (nonzero) digits is 192036096, while the sum is 71.

The spelling of 9908780377661 in words is "nine trillion, nine hundred eight billion, seven hundred eighty million, three hundred seventy-seven thousand, six hundred sixty-one".