20309992 has 8 divisors (see below), whose sum is σ = 38081250. Its totient is φ = 10154992.

The previous prime is 20309959. The next prime is 20309999. The reversal of 20309992 is 29990302.

It can be written as a sum of positive squares in only one way, i.e., 19660356 + 649636 = 4434^2 + 806^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×20309992³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20309999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1269367 + ... + 1269382.

Almost surely, 2^20309992 is an apocalyptic number.

It is an amenable number.

20309992 is a deficient number, since it is larger than the sum of its proper divisors (17771258).

20309992 is a wasteful number, since it uses less digits than its factorization.

20309992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2538755 (or 2538751 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 34.

The square root of 20309992 is about 4506.6608481225. The cubic root of 20309992 is about 272.8369907098.

The spelling of 20309992 in words is "twenty million, three hundred nine thousand, nine hundred ninety-two".