1391988297 has 8 divisors (see below), whose sum is σ = 2121125056. Its totient is φ = 795421872.

The previous prime is 1391988293. The next prime is 1391988307. The reversal of 1391988297 is 7928891931.

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

It is not a de Polignac number, because 1391988297 - 2² = 1391988293 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1391988293) 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, 33142558 + ... + 33142599.

It is an arithmetic number, because the mean of its divisors is an integer number (265140632).

Almost surely, 2^1391988297 is an apocalyptic number.

It is an amenable number.

1391988297 is a deficient number, since it is larger than the sum of its proper divisors (729136759).

1391988297 is an equidigital number, since it uses as much as digits as its factorization.

1391988297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66285167.

The product of its digits is 1959552, while the sum is 57.

The square root of 1391988297 is about 37309.3593753632. The cubic root of 1391988297 is about 1116.5509052444.

The spelling of 1391988297 in words is "one billion, three hundred ninety-one million, nine hundred eighty-eight thousand, two hundred ninety-seven".