20899967 has 12 divisors (see below), whose sum is σ = 23413320. Its totient is φ = 18635760.

The previous prime is 20899961. The next prime is 20899969. The reversal of 20899967 is 76999802.

It is not a de Polignac number, because 20899967 - 2⁴ = 20899951 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 (20899961) 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 11 ways as a sum of consecutive naturals, for example, 4784 + ... + 8042.

It is an arithmetic number, because the mean of its divisors is an integer number (1951110).

Almost surely, 2^20899967 is an apocalyptic number.

20899967 is a deficient number, since it is larger than the sum of its proper divisors (2513353).

20899967 is a wasteful number, since it uses less digits than its factorization.

20899967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3334 (or 3323 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 20899967 is about 4571.6481710648. The cubic root of 20899967 is about 275.4536512269.

The spelling of 20899967 in words is "twenty million, eight hundred ninety-nine thousand, nine hundred sixty-seven".