20918097 has 6 divisors (see below), whose sum is σ = 30215042. Its totient is φ = 13945392.

The previous prime is 20918083. The next prime is 20918099. The reversal of 20918097 is 79081902.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18870336 + 2047761 = 4344^2 + 1431^2 .

It is not a de Polignac number, because 20918097 - 2⁶ = 20918033 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (20918099) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1162108 + ... + 1162125.

Almost surely, 2^20918097 is an apocalyptic number.

It is an amenable number.

20918097 is a deficient number, since it is larger than the sum of its proper divisors (9296945).

20918097 is a wasteful number, since it uses less digits than its factorization.

20918097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2324239 (or 2324236 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 20918097 is about 4573.6306147305. The cubic root of 20918097 is about 275.5332770521.

Adding to 20918097 its reverse (79081902), we get a palindrome (99999999).

The spelling of 20918097 in words is "twenty million, nine hundred eighteen thousand, ninety-seven".