20688699 has 16 divisors (see below), whose sum is σ = 28283904. Its totient is φ = 13447200.

The previous prime is 20688697. The next prime is 20688713. The reversal of 20688699 is 99688602.

It is not a de Polignac number, because 20688699 - 2¹ = 20688697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20688691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23542 + ... + 24404.

It is an arithmetic number, because the mean of its divisors is an integer number (1767744).

Almost surely, 2^20688699 is an apocalyptic number.

20688699 is a deficient number, since it is larger than the sum of its proper divisors (7595205).

20688699 is a wasteful number, since it uses less digits than its factorization.

20688699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058.

The product of its (nonzero) digits is 373248, while the sum is 48.

The square root of 20688699 is about 4548.4831537558. The cubic root of 20688699 is about 274.5223620722.

The spelling of 20688699 in words is "twenty million, six hundred eighty-eight thousand, six hundred ninety-nine".