20709090 has 24 divisors (see below), whose sum is σ = 53843868. Its totient is φ = 5522400.

The previous prime is 20709089. The next prime is 20709121. The reversal of 20709090 is 9090702.

It can be written as a sum of positive squares in 2 ways, for example, as 19686969 + 1022121 = 4437^2 + 1011^2 .

20709090 is a modest number, since divided by 9090 gives 2070 as remainder.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 114961 + ... + 115140.

Almost surely, 2^20709090 is an apocalyptic number.

20709090 is an abundant number, since it is smaller than the sum of its proper divisors (33134778).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20709090 is a wasteful number, since it uses less digits than its factorization.

20709090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230114 (or 230111 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 27.

The square root of 20709090 is about 4550.7241182036. The cubic root of 20709090 is about 274.6125231695.

Adding to 20709090 its reverse (9090702), we get a palindrome (29799792).

The spelling of 20709090 in words is "twenty million, seven hundred nine thousand, ninety".