20697518 has 4 divisors (see below), whose sum is σ = 31046280. Its totient is φ = 10348758.

The previous prime is 20697511. The next prime is 20697559. The reversal of 20697518 is 81579602.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20697511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5174378 + ... + 5174381.

It is an arithmetic number, because the mean of its divisors is an integer number (7761570).

Almost surely, 2^20697518 is an apocalyptic number.

20697518 is a deficient number, since it is larger than the sum of its proper divisors (10348762).

20697518 is a wasteful number, since it uses less digits than its factorization.

20697518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10348761.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 20697518 is about 4549.4524945316. The cubic root of 20697518 is about 274.5613635385.

The spelling of 20697518 in words is "twenty million, six hundred ninety-seven thousand, five hundred eighteen".