1397748091 has 4 divisors (see below), whose sum is σ = 1471313800. Its totient is φ = 1324182384.

The previous prime is 1397748073. The next prime is 1397748113. The reversal of 1397748091 is 1908477931.

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 1397748091 - 2⁹ = 1397747579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397748031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36782826 + ... + 36782863.

It is an arithmetic number, because the mean of its divisors is an integer number (367828450).

Almost surely, 2^1397748091 is an apocalyptic number.

1397748091 is a deficient number, since it is larger than the sum of its proper divisors (73565709).

1397748091 is an equidigital number, since it uses as much as digits as its factorization.

1397748091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73565708.

The product of its (nonzero) digits is 381024, while the sum is 49.

The square root of 1397748091 is about 37386.4693572421. The cubic root of 1397748091 is about 1118.0888140781.

The spelling of 1397748091 in words is "one billion, three hundred ninety-seven million, seven hundred forty-eight thousand, ninety-one".