9919781380 has 12 divisors (see below), whose sum is σ = 20831540940. Its totient is φ = 3967912544.

The previous prime is 9919781351. The next prime is 9919781381. The reversal of 9919781380 is 831879199.

It can be written as a sum of positive squares in 2 ways, for example, as 3772907776 + 6146873604 = 61424^2 + 78402^2 .

It is not an unprimeable number, because it can be changed into a prime (9919781381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247994515 + ... + 247994554.

It is an arithmetic number, because the mean of its divisors is an integer number (1735961745).

Almost surely, 2^9919781380 is an apocalyptic number.

It is an amenable number.

9919781380 is an abundant number, since it is smaller than the sum of its proper divisors (10911759560).

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

9919781380 is a wasteful number, since it uses less digits than its factorization.

9919781380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495989078 (or 495989076 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 55.

The square root of 9919781380 is about 99598.0992790525. The cubic root of 9919781380 is about 2148.6583574822.

The spelling of 9919781380 in words is "nine billion, nine hundred nineteen million, seven hundred eighty-one thousand, three hundred eighty".