20982505 has 16 divisors (see below), whose sum is σ = 27523584. Its totient is φ = 15287040.

The previous prime is 20982503. The next prime is 20982553. The reversal of 20982505 is 50528902.

It is a happy number.

It is not a de Polignac number, because 20982505 - 2¹ = 20982503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20982503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1347 + ... + 6616.

It is an arithmetic number, because the mean of its divisors is an integer number (1720224).

Almost surely, 2^20982505 is an apocalyptic number.

It is an amenable number.

20982505 is a deficient number, since it is larger than the sum of its proper divisors (6541079).

20982505 is a wasteful number, since it uses less digits than its factorization.

20982505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8016.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 20982505 is about 4580.6664362296. Note that the first 3 decimals coincide. The cubic root of 20982505 is about 275.8157814660.

The spelling of 20982505 in words is "twenty million, nine hundred eighty-two thousand, five hundred five".