20699559 has 6 divisors (see below), whose sum is σ = 29899376. Its totient is φ = 13799700.

The previous prime is 20699519. The next prime is 20699561. The reversal of 20699559 is 95599602.

20699559 is a `hidden beast` number, since 2 + 0 + 6 + 99 + 559 = 666.

It is not a de Polignac number, because 20699559 - 2⁷ = 20699431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20699519) 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, 1149967 + ... + 1149984.

Almost surely, 2^20699559 is an apocalyptic number.

20699559 is a deficient number, since it is larger than the sum of its proper divisors (9199817).

20699559 is a wasteful number, since it uses less digits than its factorization.

20699559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299957 (or 2299954 counting only the distinct ones).

The product of its (nonzero) digits is 218700, while the sum is 45.

The square root of 20699559 is about 4549.6768017080. The cubic root of 20699559 is about 274.5703881523.

It can be divided in two parts, 2069 and 9559, that added together give a triangular number (11628 = T₁₅₂).

The spelling of 20699559 in words is "twenty million, six hundred ninety-nine thousand, five hundred fifty-nine".