20506473 has 32 divisors (see below), whose sum is σ = 33622400. Its totient is φ = 12270528.

The previous prime is 20506459. The next prime is 20506487. The reversal of 20506473 is 37460502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20506459) and next prime (20506487).

It is not a de Polignac number, because 20506473 - 2⁵ = 20506441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20506873) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12198 + ... + 13776.

It is an arithmetic number, because the mean of its divisors is an integer number (1050700).

Almost surely, 2^20506473 is an apocalyptic number.

It is an amenable number.

20506473 is a deficient number, since it is larger than the sum of its proper divisors (13115927).

20506473 is a wasteful number, since it uses less digits than its factorization.

20506473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638 (or 1632 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

The square root of 20506473 is about 4528.4073359184. The cubic root of 20506473 is about 273.7139866304.

Adding to 20506473 its reverse (37460502), we get a palindrome (57966975).

The spelling of 20506473 in words is "twenty million, five hundred six thousand, four hundred seventy-three".