20391097 has 8 divisors (see below), whose sum is σ = 20736000. Its totient is φ = 20049264.

The previous prime is 20391071. The next prime is 20391101. The reversal of 20391097 is 79019302.

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

It is a cyclic number.

It is not a de Polignac number, because 20391097 - 2¹¹ = 20389049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20391037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15304 + ... + 16582.

It is an arithmetic number, because the mean of its divisors is an integer number (2592000).

Almost surely, 2^20391097 is an apocalyptic number.

It is an amenable number.

20391097 is a deficient number, since it is larger than the sum of its proper divisors (344903).

20391097 is a wasteful number, since it uses less digits than its factorization.

20391097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1535.

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

The square root of 20391097 is about 4515.6502300333. The cubic root of 20391097 is about 273.1996866303.

It can be divided in two parts, 2039 and 1097, that added together give a square (3136 = 56²).

The spelling of 20391097 in words is "twenty million, three hundred ninety-one thousand, ninety-seven".