20472986 has 4 divisors (see below), whose sum is σ = 30709482. Its totient is φ = 10236492.

The previous prime is 20472973. The next prime is 20472997. The reversal of 20472986 is 68927402.

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

It can be written as a sum of positive squares in only one way, i.e., 12033961 + 8439025 = 3469^2 + 2905^2 .

It is a super-3 number, since 3×20472986³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5118245 + ... + 5118248.

Almost surely, 2^20472986 is an apocalyptic number.

20472986 is a deficient number, since it is larger than the sum of its proper divisors (10236496).

20472986 is a wasteful number, since it uses less digits than its factorization.

20472986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10236495.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 20472986 is about 4524.7083883937. The cubic root of 20472986 is about 273.5649141225.

The spelling of 20472986 in words is "twenty million, four hundred seventy-two thousand, nine hundred eighty-six".