20491550 has 12 divisors (see below), whose sum is σ = 38114376. Its totient is φ = 8196600.

The previous prime is 20491489. The next prime is 20491561. The reversal of 20491550 is 5519402.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 204866 + ... + 204965.

It is an arithmetic number, because the mean of its divisors is an integer number (3176198).

Almost surely, 2^20491550 is an apocalyptic number.

20491550 is a deficient number, since it is larger than the sum of its proper divisors (17622826).

20491550 is a wasteful number, since it uses less digits than its factorization.

20491550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409843 (or 409838 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 20491550 is about 4526.7593264940. The cubic root of 20491550 is about 273.6475746728.

The spelling of 20491550 in words is "twenty million, four hundred ninety-one thousand, five hundred fifty".