1080639991 has 8 divisors (see below), whose sum is σ = 1143475200. Its totient is φ = 1018400760.

The previous prime is 1080639979. The next prime is 1080640013. The reversal of 1080639991 is 1999360801.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1080639991 - 2¹⁹ = 1080115703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1080639961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145261 + ... + 152518.

It is an arithmetic number, because the mean of its divisors is an integer number (142934400).

Almost surely, 2^1080639991 is an apocalyptic number.

1080639991 is a deficient number, since it is larger than the sum of its proper divisors (62835209).

1080639991 is a wasteful number, since it uses less digits than its factorization.

1080639991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297989.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 1080639991 is about 32873.0891611969. The cubic root of 1080639991 is about 1026.1881889539.

The spelling of 1080639991 in words is "one billion, eighty million, six hundred thirty-nine thousand, nine hundred ninety-one".