20369999 has 4 divisors (see below), whose sum is σ = 21936936. Its totient is φ = 18803064.

The previous prime is 20369981. The next prime is 20370011. The reversal of 20369999 is 99996302.

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

It is a cyclic number.

It is not a de Polignac number, because 20369999 - 2¹⁶ = 20304463 is a prime.

It is a Duffinian number.

20369999 is a modest number, since divided by 9999 gives 2036 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20369929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 783449 + ... + 783474.

It is an arithmetic number, because the mean of its divisors is an integer number (5484234).

Almost surely, 2^20369999 is an apocalyptic number.

20369999 is a deficient number, since it is larger than the sum of its proper divisors (1566937).

20369999 is a wasteful number, since it uses less digits than its factorization.

20369999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566936.

The product of its (nonzero) digits is 236196, while the sum is 47.

The square root of 20369999 is about 4513.3135277754. The cubic root of 20369999 is about 273.1054305266.

The spelling of 20369999 in words is "twenty million, three hundred sixty-nine thousand, nine hundred ninety-nine".