1388820091 has 4 divisors (see below), whose sum is σ = 1388967184. Its totient is φ = 1388673000.

The previous prime is 1388820053. The next prime is 1388820113. The reversal of 1388820091 is 1900288831.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1388820091 - 2²⁹ = 851949179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1388820011) 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 3 ways as a sum of consecutive naturals, for example, 58335 + ... + 78616.

It is an arithmetic number, because the mean of its divisors is an integer number (347241796).

Almost surely, 2^1388820091 is an apocalyptic number.

1388820091 is a deficient number, since it is larger than the sum of its proper divisors (147093).

1388820091 is a wasteful number, since it uses less digits than its factorization.

1388820091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147092.

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 1388820091 is about 37266.8765930283. The cubic root of 1388820091 is about 1115.7031609366.

The spelling of 1388820091 in words is "one billion, three hundred eighty-eight million, eight hundred twenty thousand, ninety-one".