20661634 has 16 divisors (see below), whose sum is σ = 36144000. Its totient is φ = 8854692.

The previous prime is 20661631. The next prime is 20661643. The reversal of 20661634 is 43616602.

It is not an unprimeable number, because it can be changed into a prime (20661631) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 14374 + ... + 15745.

It is an arithmetic number, because the mean of its divisors is an integer number (2259000).

Almost surely, 2^20661634 is an apocalyptic number.

20661634 is a deficient number, since it is larger than the sum of its proper divisors (15482366).

20661634 is an equidigital number, since it uses as much as digits as its factorization.

20661634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30142 (or 30128 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 20661634 is about 4545.5070124245. The cubic root of 20661634 is about 274.4025995866.

The spelling of 20661634 in words is "twenty million, six hundred sixty-one thousand, six hundred thirty-four".