20091397 has 4 divisors (see below), whose sum is σ = 20964960. Its totient is φ = 19217836.

The previous prime is 20091391. The next prime is 20091413. The reversal of 20091397 is 79319002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20091397 - 2³ = 20091389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20091391) 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, 436747 + ... + 436792.

It is an arithmetic number, because the mean of its divisors is an integer number (5241240).

Almost surely, 2^20091397 is an apocalyptic number.

It is an amenable number.

20091397 is a deficient number, since it is larger than the sum of its proper divisors (873563).

20091397 is an equidigital number, since it uses as much as digits as its factorization.

20091397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873562.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 20091397 is about 4482.3428025978. The cubic root of 20091397 is about 271.8546161139.

The spelling of 20091397 in words is "twenty million, ninety-one thousand, three hundred ninety-seven".