19361890388 has 6 divisors (see below), whose sum is σ = 33883308186. Its totient is φ = 9680945192.

The previous prime is 19361890369. The next prime is 19361890391. The reversal of 19361890388 is 88309816391.

It can be written as a sum of positive squares in only one way, i.e., 18721901584 + 639988804 = 136828^2 + 25298^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2420236295 + ... + 2420236302.

It is an arithmetic number, because the mean of its divisors is an integer number (5647218031).

Almost surely, 2^19361890388 is an apocalyptic number.

It is an amenable number.

19361890388 is a deficient number, since it is larger than the sum of its proper divisors (14521417798).

19361890388 is a wasteful number, since it uses less digits than its factorization.

19361890388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4840472601 (or 4840472599 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 56.

The spelling of 19361890388 in words is "nineteen billion, three hundred sixty-one million, eight hundred ninety thousand, three hundred eighty-eight".