20909554 has 4 divisors (see below), whose sum is σ = 31364334. Its totient is φ = 10454776.

The previous prime is 20909533. The next prime is 20909563. The reversal of 20909554 is 45590902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19404025 + 1505529 = 4405^2 + 1227^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5227387 + ... + 5227390.

Almost surely, 2^20909554 is an apocalyptic number.

20909554 is a deficient number, since it is larger than the sum of its proper divisors (10454780).

20909554 is a wasteful number, since it uses less digits than its factorization.

20909554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10454779.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 20909554 is about 4572.6965786065. The cubic root of 20909554 is about 275.4957624652.

The spelling of 20909554 in words is "twenty million, nine hundred nine thousand, five hundred fifty-four".