20654643 has 16 divisors (see below), whose sum is σ = 29340576. Its totient is φ = 12879360.

The previous prime is 20654617. The next prime is 20654659. The reversal of 20654643 is 34645602.

It is not a de Polignac number, because 20654643 - 2¹² = 20650547 is a prime.

It is a super-2 number, since 2×20654643² = 853228554914898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20654643.

It is not an unprimeable number, because it can be changed into a prime (20654143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7653 + ... + 9993.

It is an arithmetic number, because the mean of its divisors is an integer number (1833786).

Almost surely, 2^20654643 is an apocalyptic number.

20654643 is a deficient number, since it is larger than the sum of its proper divisors (8685933).

20654643 is a wasteful number, since it uses less digits than its factorization.

20654643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2534.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 20654643 is about 4544.7379462407. The cubic root of 20654643 is about 274.3716474529.

The spelling of 20654643 in words is "twenty million, six hundred fifty-four thousand, six hundred forty-three".