1321790638 has 32 divisors (see below), whose sum is σ = 2322722304. Its totient is φ = 552413472.

The previous prime is 1321790597. The next prime is 1321790641. The reversal of 1321790638 is 8360971231.

It is a self number, because there is not a number n which added to its sum of digits gives 1321790638.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118581 + ... + 129247.

It is an arithmetic number, because the mean of its divisors is an integer number (72585072).

Almost surely, 2^1321790638 is an apocalyptic number.

1321790638 is a deficient number, since it is larger than the sum of its proper divisors (1000931666).

1321790638 is a wasteful number, since it uses less digits than its factorization.

1321790638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10896.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 1321790638 is about 36356.4387419890. The cubic root of 1321790638 is about 1097.4571117678.

The spelling of 1321790638 in words is "one billion, three hundred twenty-one million, seven hundred ninety thousand, six hundred thirty-eight".